Featured publications

2026
47.	Mohit Lal Bera, Joyce Kwan, Armando Pérez, Miguel A. García-March, Ravindra W. Chhajlany, Tobias Grass, Maciej Lewenstein, Utso Bhattacharya, Sourav Bhattacharjee A hybrid Anyon-Otto thermal machine npj Quantum Information, 12 (1), pp. 117, 2026, ISBN: 2056-6387. Links \| BibTeX @article{LalBera2026A, title = {A hybrid Anyon-Otto thermal machine}, author = {Mohit Lal Bera and Joyce Kwan and Armando Pérez and Miguel A. García-March and Ravindra W. Chhajlany and Tobias Grass and Maciej Lewenstein and Utso Bhattacharya and Sourav Bhattacharjee}, url = {https://doi.org/10.1038/s41534-026-01328-6}, doi = {10.1038/s41534-026-01328-6}, isbn = {2056-6387}, year = {2026}, date = {2026-07-24}, journal = {npj Quantum Information}, volume = {12}, number = {1}, pages = {117}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://doi.org/10.1038/s41534-026-01328-6 doi:10.1038/s41534-026-01328-6 Close
46.	Kuan-Yi Lee, Jhen-Dong Lin, Adam Miranowicz, Yueh-Nan Chen General Class of Functionals for Certifying Quantum Incompatibility Phys. Rev. Lett., 136 , pp. 120203, 2026. Links \| BibTeX @article{rsx1-zvbp, title = {General Class of Functionals for Certifying Quantum Incompatibility}, author = {Kuan-Yi Lee and Jhen-Dong Lin and Adam Miranowicz and Yueh-Nan Chen}, url = {https://link.aps.org/doi/10.1103/rsx1-zvbp}, doi = {10.1103/rsx1-zvbp}, year = {2026}, date = {2026-03-01}, journal = {Phys. Rev. Lett.}, volume = {136}, pages = {120203}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://link.aps.org/doi/10.1103/rsx1-zvbp doi:10.1103/rsx1-zvbp Close
45.	Zahra Jalali-Mola, Niklas Käming, Luca Asteria, Utso Bhattacharya, Ravindra W. Chhajlany, Klaus Sengstock, Maciej Lewenstein, Tobias Grass, Christof Weitenberg Anomalous Fluctuations of Bose-Einstein Condensates in Optical Lattices Phys. Rev. Lett., 136 , pp. 083401, 2026. Links \| BibTeX @article{jalalimola2026, title = {Anomalous Fluctuations of Bose-Einstein Condensates in Optical Lattices}, author = {Zahra Jalali-Mola and Niklas Käming and Luca Asteria and Utso Bhattacharya and Ravindra W. Chhajlany and Klaus Sengstock and Maciej Lewenstein and Tobias Grass and Christof Weitenberg}, url = {https://link.aps.org/doi/10.1103/95pq-6r5g}, doi = {10.1103/95pq-6r5g}, year = {2026}, date = {2026-02-23}, journal = {Phys. Rev. Lett.}, volume = {136}, pages = {083401}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://link.aps.org/doi/10.1103/95pq-6r5g doi:10.1103/95pq-6r5g Close
44.	Ting-Ting Ma, Jian Tang, Yun-Lan Zuo, Ran Huang, Adam Miranowicz, Franco Nori, Hui Jing Two-Polariton Blockade via Ultrastrong Light-Matter Coupling Phys. Rev. Lett., 136 , pp. 033601, 2026. Links \| BibTeX @article{Ma26, title = {Two-Polariton Blockade via Ultrastrong Light-Matter Coupling}, author = {Ting-Ting Ma and Jian Tang and Yun-Lan Zuo and Ran Huang and Adam Miranowicz and Franco Nori and Hui Jing}, url = {https://link.aps.org/doi/10.1103/nfz3-txyt}, doi = {10.1103/nfz3-txyt}, year = {2026}, date = {2026-01-01}, journal = {Phys. Rev. Lett.}, volume = {136}, pages = {033601}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://link.aps.org/doi/10.1103/nfz3-txyt doi:10.1103/nfz3-txyt Close
2025
43.	Huixin Guo, Kilian Lenz, Mateusz Gołębiewski, Ryszard Narkowicz, Jürgen Lindner, Maciej Krawczyk, Dirk Grundler Coherent Spin Waves in Curved Ferromagnetic Nanocaps of a 3D-Printed Magnonic Crystal Small, n/a (n/a), pp. e08983, 2025. Abstract \| Links \| BibTeX @article{https://doi.org/10.1002/smll.202508983, title = {Coherent Spin Waves in Curved Ferromagnetic Nanocaps of a 3D-Printed Magnonic Crystal}, author = {Huixin Guo and Kilian Lenz and Mateusz Gołębiewski and Ryszard Narkowicz and Jürgen Lindner and Maciej Krawczyk and Dirk Grundler}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/smll.202508983}, doi = {https://doi.org/10.1002/smll.202508983}, year = {2025}, date = {2025-12-30}, journal = {Small}, volume = {n/a}, number = {n/a}, pages = {e08983}, abstract = {Abstract Coherent magnon modes in a truly 3D magnonic crystal have yet to be investigated. This scientific gap exists despite numerous theoretical predictions of miniband formation and edge modes with topological protection. Such properties are key to advancing nanomagnonics for ultrafast data processing. In this work, a scalable nanotechnology for fabricating 3D magnonic crystals embedded in an on-chip microresonator is presented. It is realized by two-photon lithography of a 3D woodpile structure and atomic layer deposition of 30-nm-thick nickel film. Operated near 14 and 24 GHz, the microresonator output revealed numerous coherent magnons with distinct angular dependencies reflecting the underlying face-centered cubic lattice. Micromagnetic simulations show that the edge modes are localized within curved nanocaps and remain robust against changes in field orientation. Along an edge, they exhibit an unexpected phase evolution. These findings advance the development of functional microwave circuits with 3D magnonic crystals and strengthen their visionary prospects for edge-dominated magnon modes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Abstract Coherent magnon modes in a truly 3D magnonic crystal have yet to be investigated. This scientific gap exists despite numerous theoretical predictions of miniband formation and edge modes with topological protection. Such properties are key to advancing nanomagnonics for ultrafast data processing. In this work, a scalable nanotechnology for fabricating 3D magnonic crystals embedded in an on-chip microresonator is presented. It is realized by two-photon lithography of a 3D woodpile structure and atomic layer deposition of 30-nm-thick nickel film. Operated near 14 and 24 GHz, the microresonator output revealed numerous coherent magnons with distinct angular dependencies reflecting the underlying face-centered cubic lattice. Micromagnetic simulations show that the edge modes are localized within curved nanocaps and remain robust against changes in field orientation. Along an edge, they exhibit an unexpected phase evolution. These findings advance the development of functional microwave circuits with 3D magnonic crystals and strengthen their visionary prospects for edge-dominated magnon modes. Close https://onlinelibrary.wiley.com/doi/abs/10.1002/smll.202508983 doi:https://doi.org/10.1002/smll.202508983 Close
42.	Deng-Gao Lai, Adam Miranowicz, Franco Nori Nonreciprocal quantum synchronization Nature Communications, 16 (1), pp. 8491, 2025, ISSN: 2041-1723. Abstract \| Links \| BibTeX @article{Lai2025nc2, title = {Nonreciprocal quantum synchronization}, author = {Deng-Gao Lai and Adam Miranowicz and Franco Nori}, url = {https://doi.org/10.1038/s41467-025-63408-z}, doi = {10.1038/s41467-025-63408-z}, issn = {2041-1723}, year = {2025}, date = {2025-09-26}, journal = {Nature Communications}, volume = {16}, number = {1}, pages = {8491}, abstract = {Nonreciprocal physics is garnering enormous attention in both classical and quantum resource fields. Surprisingly, previous demonstrations have not explored nonreciprocal quantum synchronization of phonons, one of the most obvious examples of nonreciprocal quantum resources. Here we fill this gap to demonstrate the possibility of nonreciprocal quantum synchronization, revealing its counterintuitive robustness against random fabrication imperfections and thermal noise of practical devices. Specifically, phonons are synchronized in a chosen direction of light (magnetic field) but unsynchronized in the other, yielding a unique nonreciprocity of quantum synchronization. This happens by harnessing the synergy of the Sagnac and magnon-Kerr effects, leading to an opposite Sagnac-Fizeau shift and an exceptional magnon-Kerr-induced transition. Unlike previous proposals naturally restricted to the low-imperfection regime, our approach beats this limitation, owing to the magnon-Kerr-induced improvement in the resonator resilience. The study lays the foundation for generating fragile-to-robust nonreciprocal quantum resources.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Nonreciprocal physics is garnering enormous attention in both classical and quantum resource fields. Surprisingly, previous demonstrations have not explored nonreciprocal quantum synchronization of phonons, one of the most obvious examples of nonreciprocal quantum resources. Here we fill this gap to demonstrate the possibility of nonreciprocal quantum synchronization, revealing its counterintuitive robustness against random fabrication imperfections and thermal noise of practical devices. Specifically, phonons are synchronized in a chosen direction of light (magnetic field) but unsynchronized in the other, yielding a unique nonreciprocity of quantum synchronization. This happens by harnessing the synergy of the Sagnac and magnon-Kerr effects, leading to an opposite Sagnac-Fizeau shift and an exceptional magnon-Kerr-induced transition. Unlike previous proposals naturally restricted to the low-imperfection regime, our approach beats this limitation, owing to the magnon-Kerr-induced improvement in the resonator resilience. The study lays the foundation for generating fragile-to-robust nonreciprocal quantum resources. Close https://doi.org/10.1038/s41467-025-63408-z doi:10.1038/s41467-025-63408-z Close
41.	Mateusz Zelent, Maciej Krawczyk, Konstantin Y Guslienko Beyond Fixed-Size Skyrmions in Nanodots: Switchable Multistability with Ferromagnetic Rings Nano Letters, 2025, ISSN: 1530-6984. Links \| BibTeX @article{Zelent2025, title = {Beyond Fixed-Size Skyrmions in Nanodots: Switchable Multistability with Ferromagnetic Rings}, author = {Mateusz Zelent and Maciej Krawczyk and Konstantin Y Guslienko}, url = {https://doi.org/10.1021/acs.nanolett.5c02678}, doi = {10.1021/acs.nanolett.5c02678}, issn = {1530-6984}, year = {2025}, date = {2025-09-11}, journal = {Nano Letters}, publisher = {American Chemical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://doi.org/10.1021/acs.nanolett.5c02678 doi:10.1021/acs.nanolett.5c02678 Close
40.	Christoph Hotter, Adam Miranowicz, Karol Gietka Quantum Metrology in the Ultrastrong Coupling Regime of Light-Matter Interactions: Leveraging Virtual Excitations without Extracting Them Phys. Rev. Lett., 135 , pp. 100802, 2025. Links \| BibTeX @article{Hotter25prl, title = {Quantum Metrology in the Ultrastrong Coupling Regime of Light-Matter Interactions: Leveraging Virtual Excitations without Extracting Them}, author = {Christoph Hotter and Adam Miranowicz and Karol Gietka}, url = {https://link.aps.org/doi/10.1103/cxvs-5pb1}, doi = {10.1103/cxvs-5pb1}, year = {2025}, date = {2025-09-01}, journal = {Phys. Rev. Lett.}, volume = {135}, pages = {100802}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://link.aps.org/doi/10.1103/cxvs-5pb1 doi:10.1103/cxvs-5pb1 Close
39.	Deng-Gao Lai, Adam Miranowicz, Franco Nori Topological phonon blockade and its transfer via dark-mode engineering Nature Communications, 16 (1), pp. 8094, 2025, ISSN: 2041-1723. Abstract \| Links \| BibTeX @article{Lai2025nc1, title = {Topological phonon blockade and its transfer via dark-mode engineering}, author = {Deng-Gao Lai and Adam Miranowicz and Franco Nori}, url = {https://doi.org/10.1038/s41467-025-63042-9}, doi = {10.1038/s41467-025-63042-9}, issn = {2041-1723}, year = {2025}, date = {2025-08-29}, journal = {Nature Communications}, volume = {16}, number = {1}, pages = {8094}, abstract = {Unidirectional topological behavior, engendered by imposing topological operations winding around an exceptional point, is sensitive to dark modes, which allow deactivating topological operations, resulting in a complete blockade of both mode conversion and phonon transfer between dark and bright modes. Here we demonstrate how to beat this challenge and achieve a versatile yet unique nonreciprocal topological phonon transfer and blockade via dark-mode engineering. This happens by harnessing the power of synthetic magnetism, leading to an extraordinary transition between the dark-mode nonbreaking and breaking regimes, in a precise and controlled manner. Specifically, topological phonon blockade (transfer) happens in the dark-mode nonbreaking (breaking) regime, offering an exciting opportunity of switching between topological phonon blockade and its transfer on demand, which has no counterpart in previous studies. Remarkably, applying dark-mode engineering to quantum optomechanical networks can enable scalable network-based topological phonon transfer and quantum collective ground-state preparation. The proposed mechanism has general validity and can be generalized to the manipulation of various dark-state-related quantum effects, advancing the development of scalable quantum information processors. This study maps a general path towards generating a profoundly different topological quantum resource with immunity against both dark modes and dark states.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Unidirectional topological behavior, engendered by imposing topological operations winding around an exceptional point, is sensitive to dark modes, which allow deactivating topological operations, resulting in a complete blockade of both mode conversion and phonon transfer between dark and bright modes. Here we demonstrate how to beat this challenge and achieve a versatile yet unique nonreciprocal topological phonon transfer and blockade via dark-mode engineering. This happens by harnessing the power of synthetic magnetism, leading to an extraordinary transition between the dark-mode nonbreaking and breaking regimes, in a precise and controlled manner. Specifically, topological phonon blockade (transfer) happens in the dark-mode nonbreaking (breaking) regime, offering an exciting opportunity of switching between topological phonon blockade and its transfer on demand, which has no counterpart in previous studies. Remarkably, applying dark-mode engineering to quantum optomechanical networks can enable scalable network-based topological phonon transfer and quantum collective ground-state preparation. The proposed mechanism has general validity and can be generalized to the manipulation of various dark-state-related quantum effects, advancing the development of scalable quantum information processors. This study maps a general path towards generating a profoundly different topological quantum resource with immunity against both dark modes and dark states. Close https://doi.org/10.1038/s41467-025-63042-9 doi:10.1038/s41467-025-63042-9 Close
38.	Ephraim T Mathew, Andriy E. Serebryannikov, Jacek Jenczyk, Igor Iatsunskyi, Szymon Murawka, Mikołaj Lewandowski, Maciej Wiesner Raman Scattering Enhancements Due to Super- and Subradiant Collective Plasmon Modes on Large-Area 2D-Au Arrays ACS Applied Materials & Interfaces, 2025, ISSN: 1944-8244. Links \| BibTeX @article{Mathew2025, title = {Raman Scattering Enhancements Due to Super- and Subradiant Collective Plasmon Modes on Large-Area 2D-Au Arrays}, author = {Ephraim T Mathew and Andriy E. Serebryannikov and Jacek Jenczyk and Igor Iatsunskyi and Szymon Murawka and Mikołaj Lewandowski and Maciej Wiesner }, url = {https://doi.org/10.1021/acsami.5c04804}, doi = {10.1021/acsami.5c04804}, issn = {1944-8244}, year = {2025}, date = {2025-05-22}, journal = {ACS Applied Materials & Interfaces}, publisher = {American Chemical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://doi.org/10.1021/acsami.5c04804 doi:10.1021/acsami.5c04804 Close
37.	Sara Memarzadeh, Mateusz Gołębiewski, Maciej Krawczyk, Jarosław W. Kłos Nucleation and arrangement of Abrikosov vortices in hybrid superconductor–ferromagnet nanostructures Nanoscale Horiz., 10 , pp. 1453 - 1464, 2025. Abstract \| Links \| BibTeX @article{D4NH00618F, title = {Nucleation and arrangement of Abrikosov vortices in hybrid superconductor–ferromagnet nanostructures}, author = {Sara Memarzadeh and Mateusz Gołębiewski and Maciej Krawczyk and Jarosław W. Kłos}, url = {http://dx.doi.org/10.1039/D4NH00618F}, doi = {10.1039/D4NH00618F}, year = {2025}, date = {2025-05-21}, journal = {Nanoscale Horiz.}, volume = {10}, pages = {1453 - 1464}, publisher = {The Royal Society of Chemistry}, abstract = {This study investigates the nucleation, dynamics, and stationary configurations of Abrikosov vortices in hybrid superconductor–ferromagnet nanostructures subjected to inhomogeneous magnetic fields generated by a ferromagnetic nanodot. Employing the simulations based on time-dependent Ginzburg–Landau coupled with Maxwell's equations, we reveal the evolution of curved vortex structures that exhibit creep-like deformation before stabilizing. The interplay between vortices and currents confined within the superconducting nanoelement gives rise to unconventional stationary vortex arrangements, which evolve gradually with increasing magnetic field strength—a behavior absent in homogeneous fields. Our numerical results illustrate how the ferromagnetic element can control vortex configurations via a stray magnetic field—insights that are difficult to access experimentally or analytically. We demonstrate that the superconducting nanoelement can stabilize into distinct vortex states in response to even small system perturbations. This highlights the extreme sensitivity of the system and the richness of its dynamic behaviour, revealing complex pinning mechanisms and providing valuable insights into the optimisation of nanoscale superconducting systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close This study investigates the nucleation, dynamics, and stationary configurations of Abrikosov vortices in hybrid superconductor–ferromagnet nanostructures subjected to inhomogeneous magnetic fields generated by a ferromagnetic nanodot. Employing the simulations based on time-dependent Ginzburg–Landau coupled with Maxwell's equations, we reveal the evolution of curved vortex structures that exhibit creep-like deformation before stabilizing. The interplay between vortices and currents confined within the superconducting nanoelement gives rise to unconventional stationary vortex arrangements, which evolve gradually with increasing magnetic field strength—a behavior absent in homogeneous fields. Our numerical results illustrate how the ferromagnetic element can control vortex configurations via a stray magnetic field—insights that are difficult to access experimentally or analytically. We demonstrate that the superconducting nanoelement can stabilize into distinct vortex states in response to even small system perturbations. This highlights the extreme sensitivity of the system and the richness of its dynamic behaviour, revealing complex pinning mechanisms and providing valuable insights into the optimisation of nanoscale superconducting systems. Close http://dx.doi.org/10.1039/D4NH00618F doi:10.1039/D4NH00618F Close
36.	Kuan-Yi Lee, Jhen-Dong Lin, Karel Lemr, Antonín Černoch, Adam Miranowicz, Franco Nori, Huan-Yu Ku, Yueh-Nan Chen Unveiling quantum steering by quantum-classical uncertainty complementarity npj Quantum Information, 11 (1), pp. 72, 2025, ISSN: 2056-6387. Abstract \| Links \| BibTeX @article{Lee2025, title = {Unveiling quantum steering by quantum-classical uncertainty complementarity}, author = {Kuan-Yi Lee and Jhen-Dong Lin and Karel Lemr and Antonín {Č}ernoch and Adam Miranowicz and Franco Nori and Huan-Yu Ku and Yueh-Nan Chen}, url = {https://doi.org/10.1038/s41534-025-01017-w}, doi = {10.1038/s41534-025-01017-w}, issn = {2056-6387}, year = {2025}, date = {2025-05-08}, journal = {npj Quantum Information}, volume = {11}, number = {1}, pages = {72}, abstract = {One of the remarkable aspects of quantum steering is its ability to violate local uncertainty complementarity relations. In this vein of study, various steering witnesses have been developed. Here, we introduce a novel complementarity relation between the system's quantum and classical uncertainties corresponding to the distillable coherence and the von Neumann entropy, respectively. We show that the proposed complementarity relation is tighter than the entropic uncertainty relation (EUR). Leveraging this result, we propose a steering witness that is more efficient than the EUR. From the operational perspective, the steering witness quantifies the amount of extra distillable coherence facilitated by quantum steerability. Notably, the proposed steering witness serves as a full entanglement measure for pure bipartite states--an ability that the EUR lacks. We also experimentally validate such a property through a photonic system. Furthermore, a deeper connection to the uncertainty principle is revealed by showcasing the steering-induced distillable coherence can quantify measurement incompatibility and quantum steerability under genuine incoherent operations. Our work establishes a clear quantitative and operational link between coherence and steering, which are vital resources of quantum technologies, and underscores our efforts in bridging the uncertainty principle with quantum coherence.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close One of the remarkable aspects of quantum steering is its ability to violate local uncertainty complementarity relations. In this vein of study, various steering witnesses have been developed. Here, we introduce a novel complementarity relation between the system's quantum and classical uncertainties corresponding to the distillable coherence and the von Neumann entropy, respectively. We show that the proposed complementarity relation is tighter than the entropic uncertainty relation (EUR). Leveraging this result, we propose a steering witness that is more efficient than the EUR. From the operational perspective, the steering witness quantifies the amount of extra distillable coherence facilitated by quantum steerability. Notably, the proposed steering witness serves as a full entanglement measure for pure bipartite states--an ability that the EUR lacks. We also experimentally validate such a property through a photonic system. Furthermore, a deeper connection to the uncertainty principle is revealed by showcasing the steering-induced distillable coherence can quantify measurement incompatibility and quantum steerability under genuine incoherent operations. Our work establishes a clear quantitative and operational link between coherence and steering, which are vital resources of quantum technologies, and underscores our efforts in bridging the uncertainty principle with quantum coherence. Close https://doi.org/10.1038/s41534-025-01017-w doi:10.1038/s41534-025-01017-w Close
35.	Christian Brahms, Lin Zhang, Xiao Shen, Utso Bhattacharya, Maria Recasens, Johann Osmond, Tobias Grass, Ravindra W. Chhajlany, Kent A Hallman, Richard F Haglund, Sokrates T Pantelides, Maciej Lewenstein, John C Travers, Allan S Johnson Decoupled few-femtosecond phase transitions in vanadium dioxide Nature Communications, 16 (1), pp. 3714, 2025, ISBN: 2041-1723. Abstract \| Links \| BibTeX @article{Brahms2025, title = {Decoupled few-femtosecond phase transitions in vanadium dioxide}, author = {Christian Brahms and Lin Zhang and Xiao Shen and Utso Bhattacharya and Maria Recasens and Johann Osmond and Tobias Grass and Ravindra W. Chhajlany and Kent A Hallman and Richard F Haglund and Sokrates T Pantelides and Maciej Lewenstein and John C Travers and Allan S Johnson}, url = {https://doi.org/10.1038/s41467-025-58895-z}, doi = {10.1038/s41467-025-58895-z}, isbn = {2041-1723}, year = {2025}, date = {2025-04-19}, journal = {Nature Communications}, volume = {16}, number = {1}, pages = {3714}, abstract = {The nature of the insulator-to-metal phase transition in vanadium dioxide (VO2) is one of the longest-standing problems in condensed-matter physics. Ultrafast spectroscopy has long promised to determine whether the transition is primarily driven by the electronic or structural degree of freedom, but measurements to date have been stymied by their sensitivity to only one of these components and/or their limited temporal resolution. Here we use ultra-broadband few-femtosecond pump-probe spectroscopy to resolve the electronic and structural phase transitions in VO2 at their fundamental time scales. Our experiments show that the system transforms into a bad-metallic phase within 10 fs after photoexcitation, but requires another 100 fs to complete the transition, during which we observe electronic oscillations and a partial re-opening of the bandgap, signalling a transient semi-metallic state. Comparisons with tensor-network simulations and density-functional theory calculations show these features result from an unexpectedly fast structural transition, in which the vanadium dimers separate and untwist with two different timescales. Our results resolve the structural and electronic nature of the light-induced phase transition in VO2 and establish ultra-broadband few-femtosecond spectroscopy as a powerful tool for studying quantum materials out of equilibrium.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The nature of the insulator-to-metal phase transition in vanadium dioxide (VO2) is one of the longest-standing problems in condensed-matter physics. Ultrafast spectroscopy has long promised to determine whether the transition is primarily driven by the electronic or structural degree of freedom, but measurements to date have been stymied by their sensitivity to only one of these components and/or their limited temporal resolution. Here we use ultra-broadband few-femtosecond pump-probe spectroscopy to resolve the electronic and structural phase transitions in VO2 at their fundamental time scales. Our experiments show that the system transforms into a bad-metallic phase within 10 fs after photoexcitation, but requires another 100 fs to complete the transition, during which we observe electronic oscillations and a partial re-opening of the bandgap, signalling a transient semi-metallic state. Comparisons with tensor-network simulations and density-functional theory calculations show these features result from an unexpectedly fast structural transition, in which the vanadium dimers separate and untwist with two different timescales. Our results resolve the structural and electronic nature of the light-induced phase transition in VO2 and establish ultra-broadband few-femtosecond spectroscopy as a powerful tool for studying quantum materials out of equilibrium. Close https://doi.org/10.1038/s41467-025-58895-z doi:10.1038/s41467-025-58895-z Close
34.	Ichiro Inoue, Taito Osaka, Victor Tkachenko, Toru Hara, Konrad J. Kapcia, Yuichi Inubushi, Shogo Kawaguchi, Jumpei Yamada, Eiji Nishibori, Makina Yabashi, Beata Ziaja High-intensity X-ray pump-monochromatic X-ray probe technique across time zero Optica, 12 (4), pp. 530-533, 2025, ISSN: 2334-2536. Links \| BibTeX @article{Inoue2025, title = {High-intensity X-ray pump-monochromatic X-ray probe technique across time zero}, author = {Ichiro Inoue and Taito Osaka and Victor Tkachenko and Toru Hara and Konrad J. Kapcia and Yuichi Inubushi and Shogo Kawaguchi and Jumpei Yamada and Eiji Nishibori and Makina Yabashi and Beata Ziaja}, doi = {10.1364/OPTICA.555433}, issn = {2334-2536}, year = {2025}, date = {2025-04-15}, journal = {Optica}, volume = {12}, number = {4}, pages = {530-533}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close doi:10.1364/OPTICA.555433 Close
33.	Jian Tang, Yunlan Zuo, Xun-Wei Xu, Ran Huang, Adam Miranowicz, Franco Nori, Hui Jing Achieving Robust Single-Photon Blockade with a Single Nanotip Nano Letters, 25 (12), pp. 4705-4712, 2025, ISSN: 1530-6984. Links \| BibTeX @article{Tang2025, title = {Achieving Robust Single-Photon Blockade with a Single Nanotip}, author = {Jian Tang and Yunlan Zuo and Xun-Wei Xu and Ran Huang and Adam Miranowicz and Franco Nori and Hui Jing}, url = {https://doi.org/10.1021/acs.nanolett.4c05433}, doi = {10.1021/acs.nanolett.4c05433}, issn = {1530-6984}, year = {2025}, date = {2025-03-26}, journal = {Nano Letters}, volume = {25}, number = {12}, pages = {4705-4712}, publisher = {American Chemical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://doi.org/10.1021/acs.nanolett.4c05433 doi:10.1021/acs.nanolett.4c05433 Close
32.	Jhen-Dong Lin, Po-Chen Kuo, Neill Lambert, Adam Miranowicz, Franco Nori, Yueh-Nan Chen Non-Markovian quantum exceptional points Nature Communications, 16 (1), pp. 1289, 2025, ISSN: 2041-1723. Abstract \| Links \| BibTeX @article{Lin2025, title = {Non-Markovian quantum exceptional points}, author = {Jhen-Dong Lin and Po-Chen Kuo and Neill Lambert and Adam Miranowicz and Franco Nori and Yueh-Nan Chen}, url = {https://doi.org/10.1038/s41467-025-56242-w}, doi = {10.1038/s41467-025-56242-w}, issn = {2041-1723}, year = {2025}, date = {2025-02-03}, journal = {Nature Communications}, volume = {16}, number = {1}, pages = {1289}, abstract = {Exceptional points (EPs) are singularities in the spectra of non-Hermitian operators where eigenvalues and eigenvectors coalesce. Open quantum systems have recently been explored as EP testbeds due to their non-Hermitian nature. However, most studies focus on the Markovian limit, leaving a gap in understanding EPs in the non-Markovian regime. This work addresses this gap by proposing a general framework based on two numerically exact descriptions of non-Markovian dynamics: the pseudomode equation of motion (PMEOM) and the hierarchical equations of motion (HEOM). The PMEOM is particularly useful due to its Lindblad-type structure, aligning with previous studies in the Markovian regime while offering deeper insights into EP identification. This framework incorporates non-Markovian effects through auxiliary degrees of freedom, enabling the discovery of additional or higher-order EPs that are inaccessible in the Markovian regime. We demonstrate the utility of this approach using the spin-boson model and linear bosonic systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Exceptional points (EPs) are singularities in the spectra of non-Hermitian operators where eigenvalues and eigenvectors coalesce. Open quantum systems have recently been explored as EP testbeds due to their non-Hermitian nature. However, most studies focus on the Markovian limit, leaving a gap in understanding EPs in the non-Markovian regime. This work addresses this gap by proposing a general framework based on two numerically exact descriptions of non-Markovian dynamics: the pseudomode equation of motion (PMEOM) and the hierarchical equations of motion (HEOM). The PMEOM is particularly useful due to its Lindblad-type structure, aligning with previous studies in the Markovian regime while offering deeper insights into EP identification. This framework incorporates non-Markovian effects through auxiliary degrees of freedom, enabling the discovery of additional or higher-order EPs that are inaccessible in the Markovian regime. We demonstrate the utility of this approach using the spin-boson model and linear bosonic systems. Close https://doi.org/10.1038/s41467-025-56242-w doi:10.1038/s41467-025-56242-w Close
31.	Mateusz Gołębiewski, Krzysztof Szulc, Maciej Krawczyk Magnetic field controlled surface localization of ferromagnetic resonance modes in 3D nanostructures Acta Materialia, 283 , pp. 120499, 2025, ISSN: 1359-6454. Abstract \| Links \| BibTeX @article{GOLEBIEWSKI2025120499, title = {Magnetic field controlled surface localization of ferromagnetic resonance modes in 3D nanostructures}, author = {Mateusz Gołębiewski and Krzysztof Szulc and Maciej Krawczyk}, url = {https://www.sciencedirect.com/science/article/pii/S1359645424008486}, doi = {https://doi.org/10.1016/j.actamat.2024.120499}, issn = {1359-6454}, year = {2025}, date = {2025-01-15}, journal = {Acta Materialia}, volume = {283}, pages = {120499}, abstract = {By extending the current understanding and use of magnonics beyond conventional planar systems, we demonstrate the surface localization of ferromagnetic resonance (FMR) modes through the design of complex three-dimensional nanostructures. Using micromagnetic simulations, we systematically investigate woodpile-like scaffolds and gyroids — periodic chiral entities characterized by their triple junctions. The study highlights the critical role of demagnetizing fields and exchange energy in determining the FMR responses of 3D nanosystems, especially the strongly asymmetric distribution of the spin-wave mode over the system’s height. Importantly, the top–bottom dynamic switching of the surface mode localization across the structures in response to changes in magnetic field orientation provides a new method for controlling magnetization dynamics. The results demonstrate the critical role of the geometric features in dictating the dynamic magnetic behavior of three-dimensional nanostructures, paving the way for both experimental exploration and practical advances in 3D magnonics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close By extending the current understanding and use of magnonics beyond conventional planar systems, we demonstrate the surface localization of ferromagnetic resonance (FMR) modes through the design of complex three-dimensional nanostructures. Using micromagnetic simulations, we systematically investigate woodpile-like scaffolds and gyroids — periodic chiral entities characterized by their triple junctions. The study highlights the critical role of demagnetizing fields and exchange energy in determining the FMR responses of 3D nanosystems, especially the strongly asymmetric distribution of the spin-wave mode over the system’s height. Importantly, the top–bottom dynamic switching of the surface mode localization across the structures in response to changes in magnetic field orientation provides a new method for controlling magnetization dynamics. The results demonstrate the critical role of the geometric features in dictating the dynamic magnetic behavior of three-dimensional nanostructures, paving the way for both experimental exploration and practical advances in 3D magnonics. Close https://www.sciencedirect.com/science/article/pii/S1359645424008486 doi:https://doi.org/10.1016/j.actamat.2024.120499 Close
2024
30.	Wei Qin, Adam Miranowicz, Franco Nori Exponentially Improved Dispersive Qubit Readout with Squeezed Light Phys. Rev. Lett., 133 , pp. 233605, 2024. Links \| BibTeX @article{Wei2024prr, title = {Exponentially Improved Dispersive Qubit Readout with Squeezed Light}, author = {Wei Qin and Adam Miranowicz and Franco Nori}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.133.233605}, doi = {10.1103/PhysRevLett.133.233605}, year = {2024}, date = {2024-12-01}, journal = {Phys. Rev. Lett.}, volume = {133}, pages = {233605}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://link.aps.org/doi/10.1103/PhysRevLett.133.233605 doi:10.1103/PhysRevLett.133.233605 Close
29.	Ievgen I Arkhipov, Fabrizio Minganti, Adam Miranowicz, Sahin K Özdemir, Franco Nori Restoring Adiabatic State Transfer in Time-Modulated Non-Hermitian Systems Phys. Rev. Lett., 133 , pp. 113802, 2024. Links \| BibTeX @article{Arkhipov24prl, title = {Restoring Adiabatic State Transfer in Time-Modulated Non-Hermitian Systems}, author = {Ievgen I Arkhipov and Fabrizio Minganti and Adam Miranowicz and Sahin K Özdemir and Franco Nori}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.133.113802}, doi = {10.1103/PhysRevLett.133.113802}, year = {2024}, date = {2024-09-01}, journal = {Phys. Rev. Lett.}, volume = {133}, pages = {113802}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://link.aps.org/doi/10.1103/PhysRevLett.133.113802 doi:10.1103/PhysRevLett.133.113802 Close
28.	Deng-Gao Lai, Adam Miranowicz, Franco Nori Nonreciprocal Topological Phonon Transfer Independent of Both Device Mass and Exceptional-Point Encircling Direction Phys. Rev. Lett., 132 , pp. 243602, 2024. Links \| BibTeX @article{Lai24prl, title = {Nonreciprocal Topological Phonon Transfer Independent of Both Device Mass and Exceptional-Point Encircling Direction}, author = {Deng-Gao Lai and Adam Miranowicz and Franco Nori}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.132.243602}, doi = {10.1103/PhysRevLett.132.243602}, year = {2024}, date = {2024-06-01}, journal = {Phys. Rev. Lett.}, volume = {132}, pages = {243602}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://link.aps.org/doi/10.1103/PhysRevLett.132.243602 doi:10.1103/PhysRevLett.132.243602 Close
27.	Mateusz Gołębiewski, Riccardo Hertel, Massimiliano dÁquino, Vitaliy Vasyuchka, Mathias Weiler, Philipp Pirro, Maciej Krawczyk, Shunsuke Fukami, Hideo Ohno, Justin Llandro Collective Spin-Wave Dynamics in Gyroid Ferromagnetic Nanostructures ACS Applied Materials & Interfaces, 2024, ISSN: 1944-8244. Links \| BibTeX @article{Gołębiewski2024, title = {Collective Spin-Wave Dynamics in Gyroid Ferromagnetic Nanostructures}, author = {Mateusz Gołębiewski and Riccardo Hertel and Massimiliano dÁquino and Vitaliy Vasyuchka and Mathias Weiler and Philipp Pirro and Maciej Krawczyk and Shunsuke Fukami and Hideo Ohno and Justin Llandro}, url = {https://doi.org/10.1021/acsami.4c02366}, doi = {10.1021/acsami.4c02366}, issn = {1944-8244}, year = {2024}, date = {2024-04-22}, journal = {ACS Applied Materials & Interfaces}, publisher = {American Chemical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://doi.org/10.1021/acsami.4c02366 doi:10.1021/acsami.4c02366 Close
26.	Deng-Gao Lai, C -H Wang, B -P Hou, Adam Miranowicz, Franco Nori Exceptional refrigeration of motions beyond their mass and temperature limitations Optica, 11 (4), pp. 485–491, 2024. Abstract \| Links \| BibTeX @article{Lai2024b, title = {Exceptional refrigeration of motions beyond their mass and temperature limitations}, author = {Deng-Gao Lai and C -H Wang and B -P Hou and Adam Miranowicz and Franco Nori}, url = {https://opg.optica.org/optica/abstract.cfm?URI=optica-11-4-485}, doi = {10.1364/OPTICA.495199}, year = {2024}, date = {2024-04-01}, journal = {Optica}, volume = {11}, number = {4}, pages = {485--491}, publisher = {Optica Publishing Group}, abstract = {Coaxing vibrations in the regimes of both large mass and high temperature into their motional quantum ground states is extremely challenging, because it requires an ultra-high optical power, which introduces extraneous excessive heating and intricate instabilities. Here we propose how to overcome these obstacles and cool vibrational networks by simply harnessing the power of an exceptional point (EP) induced in parity-time symmetric structures; and we reveal its exceptional cooling properties otherwise unachievable in conventional devices. In stark contrast to standard-cooling protocols, a three orders-of-magnitude amplification in net cooling rates arises from the EP-cooling mechanism, without which it vanishes. Remarkably, our EP cooling is nearly immune to both resonator mass and environmental temperature, and this overthrows the consensus that poor intrinsic factors and rugged extrinsic environment suppress cooling channels. Our study offers the possibility of isolating and engineering motional properties of large-mass and high-temperature objects for various applications in optical and acoustic sensing, gravimetry, and inertial navigation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Coaxing vibrations in the regimes of both large mass and high temperature into their motional quantum ground states is extremely challenging, because it requires an ultra-high optical power, which introduces extraneous excessive heating and intricate instabilities. Here we propose how to overcome these obstacles and cool vibrational networks by simply harnessing the power of an exceptional point (EP) induced in parity-time symmetric structures; and we reveal its exceptional cooling properties otherwise unachievable in conventional devices. In stark contrast to standard-cooling protocols, a three orders-of-magnitude amplification in net cooling rates arises from the EP-cooling mechanism, without which it vanishes. Remarkably, our EP cooling is nearly immune to both resonator mass and environmental temperature, and this overthrows the consensus that poor intrinsic factors and rugged extrinsic environment suppress cooling channels. Our study offers the possibility of isolating and engineering motional properties of large-mass and high-temperature objects for various applications in optical and acoustic sensing, gravimetry, and inertial navigation. Close https://opg.optica.org/optica/abstract.cfm?URI=optica-11-4-485 doi:10.1364/OPTICA.495199 Close
25.	Nikhil Kumar, Paweł Gruszecki, Mateusz Gołębiewski, Jarosław W. Kłos, Maciej Krawczyk Exciting High-Frequency Short-Wavelength Spin Waves using High Harmonics of a Magnonic Cavity Mode Advanced Quantum Technologies, n/a (n/a), pp. 2400015, 2024. Abstract \| Links \| BibTeX @article{https://doi.org/10.1002/qute.202400015, title = {Exciting High-Frequency Short-Wavelength Spin Waves using High Harmonics of a Magnonic Cavity Mode}, author = {Nikhil Kumar and Paweł Gruszecki and Mateusz Gołębiewski and Jarosław W. Kłos and Maciej Krawczyk}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/qute.202400015}, doi = {https://doi.org/10.1002/qute.202400015}, year = {2024}, date = {2024-03-29}, journal = {Advanced Quantum Technologies}, volume = {n/a}, number = {n/a}, pages = {2400015}, abstract = {Abstract Spin waves (SWs) are promising objects for signal processing and future quantum technologies due to their high microwave frequencies with corresponding nanoscale wavelengths. However, the nano-wavelength SWs generated so far are limited to low frequencies. In the paper, using micromagnetic simulations, it is shown that a microwave-pumped SW mode confined to the cavity of a thin film magnonic crystal (MC) can be used to generate waves at tens of GHz and wavelengths well below 50 nm. These multi-frequency harmonics of the fundamental cavity mode are generated when the amplitude of the pumping microwave field exceeds a threshold, and their intensities then scale linearly with the field intensity. The frequency of the cavity mode is equal to the ferromagnetic resonance frequency of the planar ferromagnetic film, which overlaps with the magnonic bandgap, providing an efficient mechanism for confinement and magnetic field tunability. The effect reaches saturation when the microstrip feed line covers the entire cavity, making the system feasible for realization.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Abstract Spin waves (SWs) are promising objects for signal processing and future quantum technologies due to their high microwave frequencies with corresponding nanoscale wavelengths. However, the nano-wavelength SWs generated so far are limited to low frequencies. In the paper, using micromagnetic simulations, it is shown that a microwave-pumped SW mode confined to the cavity of a thin film magnonic crystal (MC) can be used to generate waves at tens of GHz and wavelengths well below 50 nm. These multi-frequency harmonics of the fundamental cavity mode are generated when the amplitude of the pumping microwave field exceeds a threshold, and their intensities then scale linearly with the field intensity. The frequency of the cavity mode is equal to the ferromagnetic resonance frequency of the planar ferromagnetic film, which overlaps with the magnonic bandgap, providing an efficient mechanism for confinement and magnetic field tunability. The effect reaches saturation when the microstrip feed line covers the entire cavity, making the system feasible for realization. Close https://onlinelibrary.wiley.com/doi/abs/10.1002/qute.202400015 doi:https://doi.org/10.1002/qute.202400015 Close
24.	Seungbeom Chin, Yong-Su Kim, Marcin Karczewski Shortcut to multipartite entanglement generation: A graph approach to boson subtractions npj Quantum Information, 10 (1), 2024, ISSN: 2056-6387. Links \| BibTeX @article{Chin2024, title = {Shortcut to multipartite entanglement generation: A graph approach to boson subtractions}, author = {Seungbeom Chin and Yong-Su Kim and Marcin Karczewski}, url = {http://dx.doi.org/10.1038/s41534-024-00845-6}, doi = {10.1038/s41534-024-00845-6}, issn = {2056-6387}, year = {2024}, date = {2024-01-01}, journal = {npj Quantum Information}, volume = {10}, number = {1}, publisher = {Springer Science and Business Media LLC}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close http://dx.doi.org/10.1038/s41534-024-00845-6 doi:10.1038/s41534-024-00845-6 Close
23.	Wei Qin, Anton Frisk Kockum, Carlos Sánchez Munoz, Adam Miranowicz, Franco Nori Quantum amplification and simulation of strong and ultrastrong coupling of light and matter Physics Reports, 1078 , pp. 1-59, 2024, ISSN: 0370-1573, (Quantum amplification and simulation of strong and ultrastrong coupling of light and matter). Abstract \| Links \| BibTeX @article{Qin2024pr, title = {Quantum amplification and simulation of strong and ultrastrong coupling of light and matter}, author = {Wei Qin and Anton Frisk Kockum and Carlos Sánchez Munoz and Adam Miranowicz and Franco Nori}, url = {https://www.sciencedirect.com/science/article/pii/S0370157324001571}, doi = {https://doi.org/10.1016/j.physrep.2024.05.003}, issn = {0370-1573}, year = {2024}, date = {2024-01-01}, journal = {Physics Reports}, volume = {1078}, pages = {1-59}, abstract = {The interaction of light and matter at the single-photon level is of central importance in various fields of physics, including, e.g., condensed matter physics, astronomy, quantum optics, and quantum information. Amplification of such quantum lightmatter interaction can be highly beneficial to, e.g., improve device performance, explore novel phenomena, and understand fundamental physics, and has therefore been a long-standing goal. Furthermore, simulation of lightmatter interaction in the regime of ultrastrong coupling, where the interaction strength is comparable to the bare frequencies of the uncoupled systems, has also become a hot research topic, and considerable progress has been made both theoretically and experimentally in the past decade. In this review, we provide a detailed introduction of recent advances in amplification of quantum lightmatter interaction and simulation of ultrastrong lightmatter interaction, particularly in cavity and circuit quantum electrodynamics and in cavity optomechanics.}, note = {Quantum amplification and simulation of strong and ultrastrong coupling of light and matter}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The interaction of light and matter at the single-photon level is of central importance in various fields of physics, including, e.g., condensed matter physics, astronomy, quantum optics, and quantum information. Amplification of such quantum lightmatter interaction can be highly beneficial to, e.g., improve device performance, explore novel phenomena, and understand fundamental physics, and has therefore been a long-standing goal. Furthermore, simulation of lightmatter interaction in the regime of ultrastrong coupling, where the interaction strength is comparable to the bare frequencies of the uncoupled systems, has also become a hot research topic, and considerable progress has been made both theoretically and experimentally in the past decade. In this review, we provide a detailed introduction of recent advances in amplification of quantum lightmatter interaction and simulation of ultrastrong lightmatter interaction, particularly in cavity and circuit quantum electrodynamics and in cavity optomechanics. Close https://www.sciencedirect.com/science/article/pii/S0370157324001571 doi:https://doi.org/10.1016/j.physrep.2024.05.003 Close
2023
22.	Javid Naikoo, Ravindra W. Chhajlany, Jan Kołodyński Multiparameter Estimation Perspective on Non-Hermitian Singularity-Enhanced Sensing Phys. Rev. Lett., 131 , pp. 220801, 2023. Abstract \| Links \| BibTeX @article{PhysRevLett.131.220801, title = {Multiparameter Estimation Perspective on Non-Hermitian Singularity-Enhanced Sensing}, author = {Javid Naikoo and Ravindra W. Chhajlany and Jan Kołodyński}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.131.220801}, doi = {10.1103/PhysRevLett.131.220801}, year = {2023}, date = {2023-11-29}, journal = {Phys. Rev. Lett.}, volume = {131}, pages = {220801}, publisher = {American Physical Society}, abstract = {Describing the evolution of quantum systems by means of non-Hermitian generators opens a new avenue to explore the dynamical properties naturally emerging in such a picture, e.g. operation at the so-called exceptional points, preservation of parity-time symmetry, or capitalizing on the singular behavior of the dynamics. In this Letter, we focus on the possibility of achieving unbounded sensitivity when using the system to sense linear perturbations away from a singular point. By combining multiparameter estimation theory of Gaussian quantum systems with the one of singular-matrix perturbations, we introduce the necessary tools to study the ultimate limits on the precision attained by such singularity-tuned sensors. We identify under what conditions and at what rate can the resulting sensitivity indeed diverge, in order to show that nuisance parameters should be generally included in the analysis, as their presence may alter the scaling of the error with the estimated parameter.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Describing the evolution of quantum systems by means of non-Hermitian generators opens a new avenue to explore the dynamical properties naturally emerging in such a picture, e.g. operation at the so-called exceptional points, preservation of parity-time symmetry, or capitalizing on the singular behavior of the dynamics. In this Letter, we focus on the possibility of achieving unbounded sensitivity when using the system to sense linear perturbations away from a singular point. By combining multiparameter estimation theory of Gaussian quantum systems with the one of singular-matrix perturbations, we introduce the necessary tools to study the ultimate limits on the precision attained by such singularity-tuned sensors. We identify under what conditions and at what rate can the resulting sensitivity indeed diverge, in order to show that nuisance parameters should be generally included in the analysis, as their presence may alter the scaling of the error with the estimated parameter. Close https://link.aps.org/doi/10.1103/PhysRevLett.131.220801 doi:10.1103/PhysRevLett.131.220801 Close
21.	Ichiro Inoue, Jumpei Yamada, Konrad J. Kapcia, Michal Stransky, Victor Tkachenko, Zoltan Jurek, Takato Inoue, Taito Osaka, Yuichi Inubushi, Atsuki Ito, Yuto Tanaka, Satoshi Matsuyama, Kazuto Yamauchi, Makina Yabashi, Beata Ziaja Femtosecond Reduction of Atomic Scattering Factors Triggered by Intense X-Ray Pulse Physical Review Letters, 131 , pp. 163201, 2023. Abstract \| Links \| BibTeX @article{Inoue2023, title = {Femtosecond Reduction of Atomic Scattering Factors Triggered by Intense X-Ray Pulse}, author = {Ichiro Inoue and Jumpei Yamada and Konrad J. Kapcia and Michal Stransky and Victor Tkachenko and Zoltan Jurek and Takato Inoue and Taito Osaka and Yuichi Inubushi and Atsuki Ito and Yuto Tanaka and Satoshi Matsuyama and Kazuto Yamauchi and Makina Yabashi and Beata Ziaja}, url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.163201}, doi = {10.1103/PhysRevLett.131.163201}, year = {2023}, date = {2023-10-17}, journal = {Physical Review Letters}, volume = {131}, pages = {163201}, abstract = {X-ray diffraction of silicon irradiated with tightly focused femtosecond x-ray pulses (photon energy, 11.5 keV; pulse duration, 6 fs) was measured at various x-ray intensities up to 4.6×10^19W/cm^2. The measurement reveals that the diffraction intensity is highly suppressed when the x-ray intensity reaches of the order of 10^19W/cm^2. With a dedicated simulation, we confirm that the observed reduction of the diffraction intensity can be attributed to the femtosecond change in individual atomic scattering factors due to the ultrafast creation of highly ionized atoms through photoionization, Auger decay, and subsequent collisional ionization. We anticipate that this ultrafast reduction of atomic scattering factor will be a basis for new x-ray nonlinear techniques, such as pulse shortening and contrast variation x-ray scattering.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close X-ray diffraction of silicon irradiated with tightly focused femtosecond x-ray pulses (photon energy, 11.5 keV; pulse duration, 6 fs) was measured at various x-ray intensities up to 4.6×10^19W/cm^2. The measurement reveals that the diffraction intensity is highly suppressed when the x-ray intensity reaches of the order of 10^19W/cm^2. With a dedicated simulation, we confirm that the observed reduction of the diffraction intensity can be attributed to the femtosecond change in individual atomic scattering factors due to the ultrafast creation of highly ionized atoms through photoionization, Auger decay, and subsequent collisional ionization. We anticipate that this ultrafast reduction of atomic scattering factor will be a basis for new x-ray nonlinear techniques, such as pulse shortening and contrast variation x-ray scattering. Close https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.163201 doi:10.1103/PhysRevLett.131.163201 Close
20.	Ri-Hua Zheng, Wen Ning, Ye-Hong Chen, Jia-Hao Lü, Li-Tuo Shen, Kai Xu, Yu-Ran Zhang, Da Xu, Hekang Li, Yan Xia, Fan Wu, Zhen-Biao Yang, Adam Miranowicz, Neill Lambert, Dongning Zheng, Heng Fan, Franco Nori, Shi-Biao Zheng Observation of a Superradiant Phase Transition with Emergent Cat States Phys. Rev. Lett., 131 , pp. 113601 , 2023. Abstract \| Links \| BibTeX @article{Zheng2023, title = {Observation of a Superradiant Phase Transition with Emergent Cat States}, author = {Ri-Hua Zheng and Wen Ning and Ye-Hong Chen and Jia-Hao Lü and Li-Tuo Shen and Kai Xu and Yu-Ran Zhang and Da Xu and Hekang Li and Yan Xia and Fan Wu and Zhen-Biao Yang and Adam Miranowicz and Neill Lambert and Dongning Zheng and Heng Fan and Franco Nori and Shi-Biao Zheng}, url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.113601}, doi = {10.1103/PhysRevLett.131.113601}, year = {2023}, date = {2023-09-11}, journal = {Phys. Rev. Lett.}, volume = {131}, pages = {113601 }, abstract = {Superradiant phase transitions (SPTs) are important for understanding light-matter interactions at the quantum level, and play a central role in criticality-enhanced quantum sensing. So far, SPTs have been observed in driven-dissipative systems, but the emergent light fields did not show any nonclassical characteristic due to the presence of strong dissipation. Here we report an experimental demonstration of the SPT featuring the emergence of a highly nonclassical photonic field, realized with a resonator coupled to a superconducting qubit, implementing the quantum Rabi model. We fully characterize the light-matter state by Wigner matrix tomography. The measured matrix elements exhibit quantum interference intrinsic of a photonic mesoscopic superposition, and reveal light-matter entanglement.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Superradiant phase transitions (SPTs) are important for understanding light-matter interactions at the quantum level, and play a central role in criticality-enhanced quantum sensing. So far, SPTs have been observed in driven-dissipative systems, but the emergent light fields did not show any nonclassical characteristic due to the presence of strong dissipation. Here we report an experimental demonstration of the SPT featuring the emergence of a highly nonclassical photonic field, realized with a resonator coupled to a superconducting qubit, implementing the quantum Rabi model. We fully characterize the light-matter state by Wigner matrix tomography. The measured matrix elements exhibit quantum interference intrinsic of a photonic mesoscopic superposition, and reveal light-matter entanglement. Close https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.113601 doi:10.1103/PhysRevLett.131.113601 Close
19.	Krzysztof Sobucki, Wojciech Śmigaj, Piotr Graczyk, Maciej Krawczyk, Paweł Gruszecki Magnon-Optic Effects with Spin-Wave Leaky Modes: Tunable Goos-Hänchen Shift and Wood’s Anomaly Nano Letters, 23 (15), pp. 6979-6984, 2023, (PMID: 37523860). Abstract \| Links \| BibTeX @article{doi:10.1021/acs.nanolett.3c01592, title = {Magnon-Optic Effects with Spin-Wave Leaky Modes: Tunable Goos-Hänchen Shift and Wood’s Anomaly}, author = {Krzysztof Sobucki and Wojciech Śmigaj and Piotr Graczyk and Maciej Krawczyk and Paweł Gruszecki}, url = {https://doi.org/10.1021/acs.nanolett.3c01592}, doi = {10.1021/acs.nanolett.3c01592}, year = {2023}, date = {2023-07-31}, journal = {Nano Letters}, volume = {23}, number = {15}, pages = {6979-6984}, abstract = {We demonstrate numerically how a spin wave (SW) beam obliquely incident on the edge of a thin film placed below a ferromagnetic stripe can excite leaky SWs guided along the stripe. During propagation, leaky waves emit energy back into the layer in the form of plane waves and several laterally shifted parallel SW beams. This resonance excitation, combined with interference effects of the reflected and re-emitted waves, results in the magnonic Wood’s anomaly and a significant increase of the Goos-Hänchen shift magnitude. This yields a unique platform to control SW reflection and transdimensional magnonic router that can transfer SWs from a 2D platform into a 1D guided mode.}, note = {PMID: 37523860}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We demonstrate numerically how a spin wave (SW) beam obliquely incident on the edge of a thin film placed below a ferromagnetic stripe can excite leaky SWs guided along the stripe. During propagation, leaky waves emit energy back into the layer in the form of plane waves and several laterally shifted parallel SW beams. This resonance excitation, combined with interference effects of the reflected and re-emitted waves, results in the magnonic Wood’s anomaly and a significant increase of the Goos-Hänchen shift magnitude. This yields a unique platform to control SW reflection and transdimensional magnonic router that can transfer SWs from a 2D platform into a 1D guided mode. Close https://doi.org/10.1021/acs.nanolett.3c01592 doi:10.1021/acs.nanolett.3c01592 Close
18.	Ievgen I. Arkhipov, Adam Miranowicz, Fabrizio Minganti, Şahin K. Özdemir, Franco Nori Dynamically crossing diabolic points while encircling exceptional curves: A programmable symmetric-asymmetric multimode switch Nature Communications, 14 (2076), 2023. Abstract \| Links \| BibTeX @article{Arkhipov2023, title = {Dynamically crossing diabolic points while encircling exceptional curves: A programmable symmetric-asymmetric multimode switch}, author = {Ievgen I. Arkhipov and Adam Miranowicz and Fabrizio Minganti and Şahin K. Özdemir and Franco Nori}, url = {https://www.nature.com/articles/s41467-023-37275-5}, doi = {doi.org/10.1038/s41467-023-37275-5}, year = {2023}, date = {2023-04-12}, journal = {Nature Communications}, volume = {14}, number = {2076}, abstract = {Nontrivial spectral properties of non-Hermitian systems can lead to intriguing effects with no counterparts in Hermitian systems. For instance, in a two-mode photonic system, by dynamically winding around an exceptional point (EP) a controlled asymmetric-symmetric mode switching can be realized. That is, the system can either end up in one of its eigenstates, regardless of the initial eigenmode, or it can switch between the two states on demand, by simply controlling the winding direction. However, for multimode systems with higher-order EPs or multiple low-order EPs, the situation can be more involved, and the ability to control asymmetric-symmetric mode switching can be impeded, due to the breakdown of adiabaticity. Here we demonstrate that this difficulty can be overcome by winding around exceptional curves by additionally crossing diabolic points. We consider a four-mode PT-symmetric bosonic system as a platform for experimental realization of such a multimode switch. Our work provides alternative routes for light manipulations in non-Hermitian photonic setups.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Nontrivial spectral properties of non-Hermitian systems can lead to intriguing effects with no counterparts in Hermitian systems. For instance, in a two-mode photonic system, by dynamically winding around an exceptional point (EP) a controlled asymmetric-symmetric mode switching can be realized. That is, the system can either end up in one of its eigenstates, regardless of the initial eigenmode, or it can switch between the two states on demand, by simply controlling the winding direction. However, for multimode systems with higher-order EPs or multiple low-order EPs, the situation can be more involved, and the ability to control asymmetric-symmetric mode switching can be impeded, due to the breakdown of adiabaticity. Here we demonstrate that this difficulty can be overcome by winding around exceptional curves by additionally crossing diabolic points. We consider a four-mode PT-symmetric bosonic system as a platform for experimental realization of such a multimode switch. Our work provides alternative routes for light manipulations in non-Hermitian photonic setups. Close https://www.nature.com/articles/s41467-023-37275-5 doi:doi.org/10.1038/s41467-023-37275-5 Close
17.	Alberto Mercurio, Shilan Abo, Fabio Mauceri, Enrico Russo, Vincenzo Macrì, Adam Miranowicz, Salvatore Savasta, Omar Di Stefano Pure Dephasing of Light-Matter Systems in the Ultrastrong and Deep-Strong Coupling Regimes Phys. Rev. Lett., 130 , pp. 123601, 2023. Abstract \| Links \| BibTeX @article{Mercurio2023, title = {Pure Dephasing of Light-Matter Systems in the Ultrastrong and Deep-Strong Coupling Regimes}, author = {Alberto Mercurio and Shilan Abo and Fabio Mauceri and Enrico Russo and Vincenzo Macrì and Adam Miranowicz and Salvatore Savasta and Omar Di Stefano}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.130.123601}, doi = {10.1103/PhysRevLett.130.123601}, year = {2023}, date = {2023-03-21}, journal = {Phys. Rev. Lett.}, volume = {130}, pages = {123601}, abstract = {Pure dephasing originates from the nondissipative information exchange between quantum systems and environments, and plays a key role in both spectroscopy and quantum information technology. Often pure dephasing constitutes the main mechanism of decay of quantum correlations. Here we investigate how pure dephasing of one of the components of a hybrid quantum system affects the dephasing rate of the system transitions. We find that, in turn, the interaction, in the case of a light-matter system, can significantly affect the form of the stochastic perturbation describing the dephasing of a subsystem, depending on the adopted gauge. Neglecting this issue can lead to wrong and unphysical results when the interaction becomes comparable to the bare resonance frequencies of subsystems, which correspond to the ultrastrong and deep-strong coupling regimes. We present results for two prototypical models of cavity quantun electrodynamics: the quantum Rabi and the Hopfield model.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Pure dephasing originates from the nondissipative information exchange between quantum systems and environments, and plays a key role in both spectroscopy and quantum information technology. Often pure dephasing constitutes the main mechanism of decay of quantum correlations. Here we investigate how pure dephasing of one of the components of a hybrid quantum system affects the dephasing rate of the system transitions. We find that, in turn, the interaction, in the case of a light-matter system, can significantly affect the form of the stochastic perturbation describing the dephasing of a subsystem, depending on the adopted gauge. Neglecting this issue can lead to wrong and unphysical results when the interaction becomes comparable to the bare resonance frequencies of subsystems, which correspond to the ultrastrong and deep-strong coupling regimes. We present results for two prototypical models of cavity quantun electrodynamics: the quantum Rabi and the Hopfield model. Close https://link.aps.org/doi/10.1103/PhysRevLett.130.123601 doi:10.1103/PhysRevLett.130.123601 Close
2022
16.	Konrad J. Kapcia, V. Tkachenko, F. Capotondi, A. Lichtenstein, S. Molodtsov, L. Müller, A. Philippi-Kobs, P. Piekarz, B. Ziaja Modeling of ultrafast X-ray induced magnetization dynamics in magnetic multilayer systems npj Computational Materials, 8 , pp. 212, 2022. Abstract \| Links \| BibTeX @article{Kapcia2022, title = {Modeling of ultrafast X-ray induced magnetization dynamics in magnetic multilayer systems}, author = {Konrad J. Kapcia and V. Tkachenko and F. Capotondi and A. Lichtenstein and S. Molodtsov and L. Müller and A. Philippi-Kobs and P. Piekarz and B. Ziaja}, url = {https://www.nature.com/articles/s41524-022-00895-4}, doi = {10.1038/s41524-022-00895-4}, year = {2022}, date = {2022-10-01}, journal = {npj Computational Materials}, volume = {8}, pages = {212}, abstract = {In this work, we report on modeling results obtained with our recently developed simulation tool enabling nanoscopic description of electronic processes in X-ray irradiated ferromagnetic materials. With this tool, we have studied the response of Co/Pt multilayer system irradiated by an ultrafast extreme ultraviolet pulse at the M-edge of Co (photon energy ~60 eV). It was previously investigated experimentally at the FERMI free-electron-laser facility, using the magnetic small-angle X-ray scattering technique. Our simulations show that the magnetic scattering signal from cobalt decreases on femtosecond timescales due to electronic excitation, relaxation, and transport processes both in the cobalt and in the platinum layers, following the trend observed in the experimental data. The confirmation of the predominant role of electronic processes for X-ray induced demagnetization in the regime below the structural damage threshold is a step toward quantitative control and manipulation of X-ray induced magnetic processes on femtosecond timescales.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close In this work, we report on modeling results obtained with our recently developed simulation tool enabling nanoscopic description of electronic processes in X-ray irradiated ferromagnetic materials. With this tool, we have studied the response of Co/Pt multilayer system irradiated by an ultrafast extreme ultraviolet pulse at the M-edge of Co (photon energy ~60 eV). It was previously investigated experimentally at the FERMI free-electron-laser facility, using the magnetic small-angle X-ray scattering technique. Our simulations show that the magnetic scattering signal from cobalt decreases on femtosecond timescales due to electronic excitation, relaxation, and transport processes both in the cobalt and in the platinum layers, following the trend observed in the experimental data. The confirmation of the predominant role of electronic processes for X-ray induced demagnetization in the regime below the structural damage threshold is a step toward quantitative control and manipulation of X-ray induced magnetic processes on femtosecond timescales. Close https://www.nature.com/articles/s41524-022-00895-4 doi:10.1038/s41524-022-00895-4 Close
15.	Tomoyuki Yokouchi, Satoshi Sugimoto, Bivas Rana, Shinichiro Seki, Naoki Ogawa, Yuki Shiomi, Shinya Kasai, Yoshichika Otani Pattern recognition with neuromorphic computing using magnetic field-induced dynamics of skyrmions Science Advances, 8 (39), pp. eabq5652, 2022. Abstract \| Links \| BibTeX @article{doi:10.1126/sciadv.abq5652, title = {Pattern recognition with neuromorphic computing using magnetic field-induced dynamics of skyrmions}, author = {Tomoyuki Yokouchi and Satoshi Sugimoto and Bivas Rana and Shinichiro Seki and Naoki Ogawa and Yuki Shiomi and Shinya Kasai and Yoshichika Otani}, url = {https://www.science.org/doi/pdf/10.1126/sciadv.abq5652}, doi = {10.1126/sciadv.abq5652}, year = {2022}, date = {2022-09-30}, journal = {Science Advances}, volume = {8}, number = {39}, pages = {eabq5652}, abstract = {Nonlinear phenomena in physical systems can be used for brain-inspired computing with low energy consumption. Response from the dynamics of a topological spin structure called skyrmion is one of the candidates for such a neuromorphic computing. However, its ability has not been well explored experimentally. Here, we experimentally demonstrate neuromorphic computing using nonlinear response originating from magnetic field–induced dynamics of skyrmions. We designed a simple-structured skyrmion-based neuromorphic device and succeeded in handwritten digit recognition with the accuracy as large as 94.7% and waveform recognition. Notably, there exists a positive correlation between the recognition accuracy and the number of skyrmions in the devices. The large degrees of freedom of skyrmion systems, such as the position and the size, originate from the more complex nonlinear mapping, the larger output dimension, and, thus, high accuracy. Our results provide a guideline for developing energy-saving and high-performance skyrmion neuromorphic computing devices. Skyrmion-based neuromorphic computing device recognizes waveforms and handwritten digits with high accuracy.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Nonlinear phenomena in physical systems can be used for brain-inspired computing with low energy consumption. Response from the dynamics of a topological spin structure called skyrmion is one of the candidates for such a neuromorphic computing. However, its ability has not been well explored experimentally. Here, we experimentally demonstrate neuromorphic computing using nonlinear response originating from magnetic field–induced dynamics of skyrmions. We designed a simple-structured skyrmion-based neuromorphic device and succeeded in handwritten digit recognition with the accuracy as large as 94.7% and waveform recognition. Notably, there exists a positive correlation between the recognition accuracy and the number of skyrmions in the devices. The large degrees of freedom of skyrmion systems, such as the position and the size, originate from the more complex nonlinear mapping, the larger output dimension, and, thus, high accuracy. Our results provide a guideline for developing energy-saving and high-performance skyrmion neuromorphic computing devices. Skyrmion-based neuromorphic computing device recognizes waveforms and handwritten digits with high accuracy. Close https://www.science.org/doi/pdf/10.1126/sciadv.abq5652 doi:10.1126/sciadv.abq5652 Close
14.	Wei Qin, Adam Miranowicz, Franco Nori Beating the 3 dB Limit for Intracavity Squeezing and Its Application to Nondemolition Qubit Readout Phys. Rev. Lett., 129 , pp. 123602, 2022. Abstract \| Links \| BibTeX @article{Qin2022, title = {Beating the 3 dB Limit for Intracavity Squeezing and Its Application to Nondemolition Qubit Readout}, author = {Wei Qin and Adam Miranowicz and Franco Nori}, url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.123602}, doi = {10.1103/PhysRevLett.129.123602}, year = {2022}, date = {2022-09-14}, journal = {Phys. Rev. Lett.}, volume = {129}, pages = {123602}, abstract = {While the squeezing of a propagating field can, in principle, be made arbitrarily strong, the cavity-field squeezing is subject to the well-known 3 dB limit, and thus has limited applications. Here, we propose the use of a fully quantum degenerate parametric amplifier (DPA) to beat this squeezing limit. Specifically, we show that by simply applying a two-tone driving to the signal mode, the pump mode can, counterintuitively, be driven by the photon loss of the signal mode into a squeezed steady state with, in principle, an arbitrarily high degree of squeezing. Furthermore, we demonstrate that this intracavity squeezing can increase the signal-to-noise ratio of longitudinal qubit readout exponentially with the degree of squeezing. Correspondingly, an improvement of the measurement error by many orders of magnitude can be achieved even for modest parameters. In stark contrast, using intracavity squeezing of the semiclassical DPA cannot practically increase the signal-to-noise ratio and thus improve the measurement error. Our results extend the range of applications of DPAs and open up new opportunities for modern quantum technologies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close While the squeezing of a propagating field can, in principle, be made arbitrarily strong, the cavity-field squeezing is subject to the well-known 3 dB limit, and thus has limited applications. Here, we propose the use of a fully quantum degenerate parametric amplifier (DPA) to beat this squeezing limit. Specifically, we show that by simply applying a two-tone driving to the signal mode, the pump mode can, counterintuitively, be driven by the photon loss of the signal mode into a squeezed steady state with, in principle, an arbitrarily high degree of squeezing. Furthermore, we demonstrate that this intracavity squeezing can increase the signal-to-noise ratio of longitudinal qubit readout exponentially with the degree of squeezing. Correspondingly, an improvement of the measurement error by many orders of magnitude can be achieved even for modest parameters. In stark contrast, using intracavity squeezing of the semiclassical DPA cannot practically increase the signal-to-noise ratio and thus improve the measurement error. Our results extend the range of applications of DPAs and open up new opportunities for modern quantum technologies. Close https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.123602 doi:10.1103/PhysRevLett.129.123602 Close
13.	X.-G. Wang, Guang-hua Guo, Anna Dyrdał, Józef Barnaś, V. K. Dugaev, S. S. P. Parkin, A. Ernst, L. Chotorlishvili Skyrmion Echo in a System of Interacting Skyrmions Phys. Rev. Lett., 129 , pp. 126101, 2022. Abstract \| Links \| BibTeX @article{Wang2022, title = {Skyrmion Echo in a System of Interacting Skyrmions}, author = {X.-G. Wang and Guang-hua Guo and Anna Dyrdał and Józef Barnaś and V. K. Dugaev and S. S. P. Parkin and A. Ernst and L. Chotorlishvili}, url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.126101}, doi = {10.1103/PhysRevLett.129.126101}, year = {2022}, date = {2022-09-14}, journal = {Phys. Rev. Lett.}, volume = {129}, pages = {126101}, abstract = {We consider helical rotation of skyrmions confined in the potentials formed by nanodisks. Based on numerical and analytical calculations we propose the skyrmion echo phenomenon. The physical mechanism of the skyrmion echo formation is also proposed. Because of the distortion of the lattice, impurities, or pinning effect, confined skyrmions experience slightly different local fields, which leads to dephasing of the initial signal. The interaction between skyrmions also can contribute to the dephasing process. However, switching the magnetization direction in the nanodiscs (e.g., by spin transfer torque) also switches the helical rotation of the skyrmions from clockwise to anticlockwise (or vice versa), and this restores the initial signal (which is the essence of skyrmion echo).}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We consider helical rotation of skyrmions confined in the potentials formed by nanodisks. Based on numerical and analytical calculations we propose the skyrmion echo phenomenon. The physical mechanism of the skyrmion echo formation is also proposed. Because of the distortion of the lattice, impurities, or pinning effect, confined skyrmions experience slightly different local fields, which leads to dephasing of the initial signal. The interaction between skyrmions also can contribute to the dephasing process. However, switching the magnetization direction in the nanodiscs (e.g., by spin transfer torque) also switches the helical rotation of the skyrmions from clockwise to anticlockwise (or vice versa), and this restores the initial signal (which is the essence of skyrmion echo). Close https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.126101 doi:10.1103/PhysRevLett.129.126101 Close
12.	C. Lagoin, U. Bhattacharya, T. Grass, Ravindra W. Chhajlany, T. Salamon, K. Baldwin, L. Pfeiffer, M. Lewenstein, M. Holzmann, F. Dubin Extended Bose–Hubbard model with dipolar excitons Nature, 609 , pp. 485–489, 2022. Abstract \| Links \| BibTeX @article{Lagoin2022, title = {Extended Bose–Hubbard model with dipolar excitons}, author = {C. Lagoin and U. Bhattacharya and T. Grass and Ravindra W. Chhajlany and T. Salamon and K. Baldwin and L. Pfeiffer and M. Lewenstein and M. Holzmann and F. Dubin}, url = {https://www.nature.com/articles/s41586-022-05123-z}, doi = {10.1038/s41586-022-05123-z}, year = {2022}, date = {2022-09-14}, journal = {Nature}, volume = {609}, pages = {485–489}, abstract = {The Hubbard model constitutes one of the most celebrated theoretical frameworks of condensed-matter physics. It describes strongly correlated phases of interacting quantum particles confined in lattice potentials. For bosons, the Hubbard Hamiltonian has been deeply scrutinized for short-range on-site interactions. However, accessing longer-range couplings has remained elusive experimentally. This marks the frontier towards the extended Bose–Hubbard Hamiltonian, which enables insulating ordered phases at fractional lattice fillings. Here we implement this Hamiltonian by confining semiconductor dipolar excitons in an artificial two-dimensional square lattice. Strong dipolar repulsions between nearest-neighbour lattice sites then stabilize an insulating state at half filling. This characteristic feature of the extended Bose–Hubbard model exhibits the signatures theoretically expected for a chequerboard spatial order. Our work thus highlights that dipolar excitons enable controlled implementations of boson-like arrays with strong off-site interactions, in lattices with programmable geometries and more than 100 sites.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The Hubbard model constitutes one of the most celebrated theoretical frameworks of condensed-matter physics. It describes strongly correlated phases of interacting quantum particles confined in lattice potentials. For bosons, the Hubbard Hamiltonian has been deeply scrutinized for short-range on-site interactions. However, accessing longer-range couplings has remained elusive experimentally. This marks the frontier towards the extended Bose–Hubbard Hamiltonian, which enables insulating ordered phases at fractional lattice fillings. Here we implement this Hamiltonian by confining semiconductor dipolar excitons in an artificial two-dimensional square lattice. Strong dipolar repulsions between nearest-neighbour lattice sites then stabilize an insulating state at half filling. This characteristic feature of the extended Bose–Hubbard model exhibits the signatures theoretically expected for a chequerboard spatial order. Our work thus highlights that dipolar excitons enable controlled implementations of boson-like arrays with strong off-site interactions, in lattices with programmable geometries and more than 100 sites. Close https://www.nature.com/articles/s41586-022-05123-z doi:10.1038/s41586-022-05123-z Close
11.	Krzysztof Szulc, Silvia Tacchi, Aurelio Hierro-Rodríguez, Javier Díaz, Paweł Gruszecki, Piotr Graczyk, Carlos Quirós, Daniel Markó, José Ignacio Martín, María Vélez, David S Schmool, Giovanni Carlotti, Maciej Krawczyk, Luis Manuel Álvarez-Prado Reconfigurable Magnonic Crystals Based on Imprinted Magnetization Textures in Hard and Soft Dipolar-Coupled Bilayers ACS Nano, 0 (0), pp. 0, 2022, (PMID: 36043881). Abstract \| Links \| BibTeX @article{doi:10.1021/acsnano.2c04256, title = {Reconfigurable Magnonic Crystals Based on Imprinted Magnetization Textures in Hard and Soft Dipolar-Coupled Bilayers}, author = {Krzysztof Szulc and Silvia Tacchi and Aurelio Hierro-Rodríguez and Javier Díaz and Paweł Gruszecki and Piotr Graczyk and Carlos Quirós and Daniel Markó and José Ignacio Martín and María Vélez and David S Schmool and Giovanni Carlotti and Maciej Krawczyk and Luis Manuel Álvarez-Prado}, url = {https://doi.org/10.1021/acsnano.2c04256}, doi = {10.1021/acsnano.2c04256}, year = {2022}, date = {2022-08-31}, journal = {ACS Nano}, volume = {0}, number = {0}, pages = {0}, abstract = {Reconfigurable magnetization textures offer control of spin waves with promising properties for future low-power beyond-CMOS systems. However, materials with perpendicular magnetic anisotropy (PMA) suitable for stable magnetization-texture formation are characterized by high damping, which limits their applicability in magnonic devices. Here, we propose to overcome this limitation by using hybrid structures, i.e., a PMA layer magnetostatically coupled to a low-damping soft ferromagnetic film. We experimentally show that a periodic stripe-domain texture from a PMA layer is imprinted upon the soft layer and induces a nonreciprocal dispersion relation of the spin waves confined to the low-damping film. Moreover, an asymmetric bandgap features the spin-wave band diagram, which is a clear demonstration of collective spin-wave dynamics, a property characteristic for magnonic crystals with broken time-reversal symmetry. The composite character of the hybrid structure allows for stabilization of two magnetic states at remanence, with parallel and antiparallel orientation of net magnetization in hard and soft layers. The states can be switched using a low external magnetic field; therefore, the proposed system obtains an additional functionality of state reconfigurability. This study offers a link between reconfigurable magnetization textures and low-damping spin-wave dynamics, providing an opportunity to create miniaturized, programmable, and energy-efficient signal processing devices operating at high frequencies.}, note = {PMID: 36043881}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Reconfigurable magnetization textures offer control of spin waves with promising properties for future low-power beyond-CMOS systems. However, materials with perpendicular magnetic anisotropy (PMA) suitable for stable magnetization-texture formation are characterized by high damping, which limits their applicability in magnonic devices. Here, we propose to overcome this limitation by using hybrid structures, i.e., a PMA layer magnetostatically coupled to a low-damping soft ferromagnetic film. We experimentally show that a periodic stripe-domain texture from a PMA layer is imprinted upon the soft layer and induces a nonreciprocal dispersion relation of the spin waves confined to the low-damping film. Moreover, an asymmetric bandgap features the spin-wave band diagram, which is a clear demonstration of collective spin-wave dynamics, a property characteristic for magnonic crystals with broken time-reversal symmetry. The composite character of the hybrid structure allows for stabilization of two magnetic states at remanence, with parallel and antiparallel orientation of net magnetization in hard and soft layers. The states can be switched using a low external magnetic field; therefore, the proposed system obtains an additional functionality of state reconfigurability. This study offers a link between reconfigurable magnetization textures and low-damping spin-wave dynamics, providing an opportunity to create miniaturized, programmable, and energy-efficient signal processing devices operating at high frequencies. Close https://doi.org/10.1021/acsnano.2c04256 doi:10.1021/acsnano.2c04256 Close
10.	Deng-Gao Lai, Jie-Qiao Liao, Adam Miranowicz, Franco Nori Noise-Tolerant Optomechanical Entanglement via Synthetic Magnetism Phys. Rev. Lett., 129 , pp. 063602, 2022. Abstract \| Links \| BibTeX @article{Lai2022c, title = {Noise-Tolerant Optomechanical Entanglement via Synthetic Magnetism}, author = {Deng-Gao Lai and Jie-Qiao Liao and Adam Miranowicz and Franco Nori}, url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.063602}, doi = {10.1103/PhysRevLett.129.063602}, year = {2022}, date = {2022-08-03}, journal = {Phys. Rev. Lett.}, volume = {129}, pages = {063602}, abstract = {Entanglement of light and multiple vibrations is a key resource for multichannel quantum information processing and memory. However, entanglement generation is generally suppressed, or even fully destroyed, by the dark-mode (DM) effect induced by the coupling of multiple degenerate or near-degenerate vibrational modes to a common optical mode. Here we propose how to generate optomechanical entanglement via DM breaking induced by synthetic magnetism. We find that at nonzero temperature, light and vibrations are separable in the DM-unbreaking regime but entangled in the DM-breaking regime. Remarkably, the threshold thermal phonon number for preserving entanglement in our simulations has been observed to be up to 3 orders of magnitude stronger than that in the DM-unbreaking regime. The application of the DM-breaking mechanism to optomechanical networks can make noise-tolerant entanglement networks feasible. These results are quite general and can initiate advances in quantum resources with immunity against both dark modes and thermal noise.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Entanglement of light and multiple vibrations is a key resource for multichannel quantum information processing and memory. However, entanglement generation is generally suppressed, or even fully destroyed, by the dark-mode (DM) effect induced by the coupling of multiple degenerate or near-degenerate vibrational modes to a common optical mode. Here we propose how to generate optomechanical entanglement via DM breaking induced by synthetic magnetism. We find that at nonzero temperature, light and vibrations are separable in the DM-unbreaking regime but entangled in the DM-breaking regime. Remarkably, the threshold thermal phonon number for preserving entanglement in our simulations has been observed to be up to 3 orders of magnitude stronger than that in the DM-unbreaking regime. The application of the DM-breaking mechanism to optomechanical networks can make noise-tolerant entanglement networks feasible. These results are quite general and can initiate advances in quantum resources with immunity against both dark modes and thermal noise. Close https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.129.063602 doi:10.1103/PhysRevLett.129.063602 Close
9.	Ichiro Inoue, Victor Tkachenko, Konrad J. Kapcia, Vladimir Lipp, Beata Ziaja, Yuichi Inubushi, Toru Hara, Makina Yabashi, Eiji Nishibori Delayed Onset and Directionality of X-Ray-Induced Atomic Displacements Observed on Subatomic Length Scales Phys. Rev. Lett., 128 , pp. 223203, 2022. Abstract \| Links \| BibTeX @article{Inoue2022, title = {Delayed Onset and Directionality of X-Ray-Induced Atomic Displacements Observed on Subatomic Length Scales}, author = {Ichiro Inoue and Victor Tkachenko and Konrad J. Kapcia and Vladimir Lipp and Beata Ziaja and Yuichi Inubushi and Toru Hara and Makina Yabashi and Eiji Nishibori}, url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.128.223203}, doi = {10.1103/PhysRevLett.128.223203}, year = {2022}, date = {2022-06-01}, journal = {Phys. Rev. Lett.}, volume = {128}, pages = {223203}, abstract = {Transient structural changes of Al2O3 on subatomic length scales following irradiation with an intense x-ray laser pulse (photon energy: 8.70 keV; pulse duration: 6 fs; fluence: 8×102 J/cm2) have been investigated by using an x-ray pump x-ray probe technique. The measurement reveals that aluminum and oxygen atoms remain in their original positions by ∼20 fs after the intensity maximum of the pump pulse, followed by directional atomic displacements at the fixed unit cell parameters. By comparing the experimental results and theoretical simulations, we interpret that electron excitation and relaxation triggered by the pump pulse modify the potential energy surface and drives the directional atomic displacements. Our results indicate that high-resolution x-ray structural analysis with the accuracy of 0.01 Å is feasible even with intense x-ray pulses by making the pulse duration shorter than the timescale needed to complete electron excitation and relaxation processes, which usually take up to a few tens of femtoseconds.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Transient structural changes of Al2O3 on subatomic length scales following irradiation with an intense x-ray laser pulse (photon energy: 8.70 keV; pulse duration: 6 fs; fluence: 8×102 J/cm2) have been investigated by using an x-ray pump x-ray probe technique. The measurement reveals that aluminum and oxygen atoms remain in their original positions by ∼20 fs after the intensity maximum of the pump pulse, followed by directional atomic displacements at the fixed unit cell parameters. By comparing the experimental results and theoretical simulations, we interpret that electron excitation and relaxation triggered by the pump pulse modify the potential energy surface and drives the directional atomic displacements. Our results indicate that high-resolution x-ray structural analysis with the accuracy of 0.01 Å is feasible even with intense x-ray pulses by making the pulse duration shorter than the timescale needed to complete electron excitation and relaxation processes, which usually take up to a few tens of femtoseconds. Close https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.128.223203 doi:10.1103/PhysRevLett.128.223203 Close
8.	Huan-Yu Ku, Josef Kadlec, Antonín Černoch, Marco Túlio Quintino, Wenbin Zhou, Karel Lemr, Neill Lambert, Adam Miranowicz, Shin-Liang Chen, Franco Nori, Yueh-Nan Chen Quantifying Quantumness of Channels Without Entanglement PRX Quantum, 3 , pp. 020338, 2022. Abstract \| Links \| BibTeX @article{Ku2022, title = {Quantifying Quantumness of Channels Without Entanglement}, author = {Huan-Yu Ku and Josef Kadlec and Antonín Černoch and Marco Túlio Quintino and Wenbin Zhou and Karel Lemr and Neill Lambert and Adam Miranowicz and Shin-Liang Chen and Franco Nori and Yueh-Nan Chen}, url = {https://journals.aps.org/prxquantum/abstract/10.1103/PRXQuantum.3.020338}, doi = {10.1103/PRXQuantum.3.020338}, year = {2022}, date = {2022-05-19}, journal = {PRX Quantum}, volume = {3}, pages = {020338}, abstract = {Quantum channels breaking entanglement, incompatibility, or nonlocality are defined as such because they are not useful for entanglement-based, one-sided device-independent, or device-independent quantum-information processing, respectively. Here, we show that such breaking channels are related to complementary tests of macrorealism, i.e., temporal separability, channel unsteerability, temporal unsteerability, and the temporal Bell inequality. To demonstrate this we first define a steerability-breaking channel, which is conceptually similar to entanglement and nonlocality-breaking channels and prove that it is identical to an incompatibility-breaking channel. A hierarchy of quantum nonbreaking channels is derived, akin to the existing hierarchy relations for temporal and spatial quantum correlations. We then introduce the concept of channels that break temporal correlations, explain how they are related to the standard breaking channels, and prove the following results. (1) A robustness-based measure for non-entanglement-breaking channels can be probed by temporal nonseparability. (2) A non-steerability-breaking channel can be quantified by channel steering. (3) Temporal steerability and nonmacrorealism can be used for, respectively, distinguishing unital steerability-breaking channels and nonlocality-breaking channels for a maximally entangled state. Finally, a two-dimensional depolarizing channel is experimentally implemented as a proof-of-principle example to demonstrate the hierarchy relation of nonbreaking channels using temporal quantum correlations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Quantum channels breaking entanglement, incompatibility, or nonlocality are defined as such because they are not useful for entanglement-based, one-sided device-independent, or device-independent quantum-information processing, respectively. Here, we show that such breaking channels are related to complementary tests of macrorealism, i.e., temporal separability, channel unsteerability, temporal unsteerability, and the temporal Bell inequality. To demonstrate this we first define a steerability-breaking channel, which is conceptually similar to entanglement and nonlocality-breaking channels and prove that it is identical to an incompatibility-breaking channel. A hierarchy of quantum nonbreaking channels is derived, akin to the existing hierarchy relations for temporal and spatial quantum correlations. We then introduce the concept of channels that break temporal correlations, explain how they are related to the standard breaking channels, and prove the following results. (1) A robustness-based measure for non-entanglement-breaking channels can be probed by temporal nonseparability. (2) A non-steerability-breaking channel can be quantified by channel steering. (3) Temporal steerability and nonmacrorealism can be used for, respectively, distinguishing unital steerability-breaking channels and nonlocality-breaking channels for a maximally entangled state. Finally, a two-dimensional depolarizing channel is experimentally implemented as a proof-of-principle example to demonstrate the hierarchy relation of nonbreaking channels using temporal quantum correlations. Close https://journals.aps.org/prxquantum/abstract/10.1103/PRXQuantum.3.020338 doi:10.1103/PRXQuantum.3.020338 Close
2021
7.	Ying Li, Ya-Feng Jiao, Jing-Xue Liu, Adam Miranowicz, Yun-Lan Zuo, Le-Man Kuang, Hui Jing Vector optomechanical entanglement Nanophotonics, 11 (1), pp. 67–77, 2021. Abstract \| Links \| BibTeX @article{Li2021, title = {Vector optomechanical entanglement}, author = {Ying Li and Ya-Feng Jiao and Jing-Xue Liu and Adam Miranowicz and Yun-Lan Zuo and Le-Man Kuang and Hui Jing}, url = {https://doi.org/10.1515/nanoph-2021-0485}, doi = {10.1515/nanoph-2021-0485}, year = {2021}, date = {2021-11-02}, journal = {Nanophotonics}, volume = {11}, number = {1}, pages = {67--77}, abstract = {The polarizations of optical fields, besides field intensities, provide more degrees of freedom to manipulate coherent light–matter interactions. Here, we propose how to achieve a coherent switch of optomechanical entanglement in a polarized-light-driven cavity system. We show that by tuning the polarizations of the driving field, the effective optomechanical coupling can be well controlled and, as a result, quantum entanglement between the mechanical oscillator and the optical transverse electric mode can be coherently and reversibly switched to that between the same phonon mode and the optical transverse magnetic mode. This ability to switch optomechanical entanglement with such a vectorial device can be important for building a quantum network being capable of efficient quantum information interchanges between processing nodes and flying photons.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The polarizations of optical fields, besides field intensities, provide more degrees of freedom to manipulate coherent light–matter interactions. Here, we propose how to achieve a coherent switch of optomechanical entanglement in a polarized-light-driven cavity system. We show that by tuning the polarizations of the driving field, the effective optomechanical coupling can be well controlled and, as a result, quantum entanglement between the mechanical oscillator and the optical transverse electric mode can be coherently and reversibly switched to that between the same phonon mode and the optical transverse magnetic mode. This ability to switch optomechanical entanglement with such a vectorial device can be important for building a quantum network being capable of efficient quantum information interchanges between processing nodes and flying photons. Close https://doi.org/10.1515/nanoph-2021-0485 doi:10.1515/nanoph-2021-0485 Close
6.	Cătălin Paşcu Moca, Ireneusz Weymann, Miklós Antal Werner, Gergely Zaránd Kondo Cloud in a Superconductor Phys. Rev. Lett., 127 , pp. 186804, 2021. Abstract \| Links \| BibTeX @article{Moca2021, title = {Kondo Cloud in a Superconductor}, author = {Cătălin Paşcu Moca and Ireneusz Weymann and Miklós Antal Werner and Gergely Zaránd}, url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.127.186804}, doi = {10.1103/PhysRevLett.127.186804}, year = {2021}, date = {2021-10-27}, journal = {Phys. Rev. Lett.}, volume = {127}, pages = {186804}, abstract = {Magnetic impurities embedded in a metal are screened by the Kondo effect, signaled by the formation of an extended correlation cloud, the so-called Kondo or screening cloud. In a superconductor, the Kondo state turns into subgap Yu-Shiba-Rusinov states, and a quantum phase transition occurs between screened and unscreened phases once the superconducting energy gap Δ exceeds sufficiently the Kondo temperature, TK. Here we show that, although the Kondo state does not form in the unscreened phase, the Kondo cloud does exist in both quantum phases. However, while screening is complete in the screened phase, it is only partial in the unscreened phase. Compensation, a quantity introduced to characterize the integrity of the cloud, is universal, and shown to be related to the magnetic impurities’ g factor, monitored experimentally by bias spectroscopy.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Magnetic impurities embedded in a metal are screened by the Kondo effect, signaled by the formation of an extended correlation cloud, the so-called Kondo or screening cloud. In a superconductor, the Kondo state turns into subgap Yu-Shiba-Rusinov states, and a quantum phase transition occurs between screened and unscreened phases once the superconducting energy gap Δ exceeds sufficiently the Kondo temperature, TK. Here we show that, although the Kondo state does not form in the unscreened phase, the Kondo cloud does exist in both quantum phases. However, while screening is complete in the screened phase, it is only partial in the unscreened phase. Compensation, a quantity introduced to characterize the integrity of the cloud, is universal, and shown to be related to the magnetic impurities’ g factor, monitored experimentally by bias spectroscopy. Close https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.127.186804 doi:10.1103/PhysRevLett.127.186804 Close
5.	Wei Qin, Adam Miranowicz, Hui Jing, Franco Nori Generating Long-Lived Macroscopically Distinct Superposition States in Atomic Ensembles Phys. Rev. Lett., 127 , pp. 093602, 2021. Abstract \| Links \| BibTeX @article{Qin2021, title = {Generating Long-Lived Macroscopically Distinct Superposition States in Atomic Ensembles}, author = {Wei Qin and Adam Miranowicz and Hui Jing and Franco Nori}, url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.127.093602}, doi = {10.1103/PhysRevLett.127.093602}, year = {2021}, date = {2021-08-23}, journal = {Phys. Rev. Lett.}, volume = {127}, pages = {093602}, abstract = {We propose to create and stabilize long-lived macroscopic quantum superposition states in atomic ensembles. We show that using a fully quantum parametric amplifier can cause the simultaneous decay of two atoms and, in turn, create stabilized atomic Schrödinger cat states. Remarkably, even with modest parameters these intracavity atomic cat states can have an extremely long lifetime, up to 4 orders of magnitude longer than that of intracavity photonic cat states under the same parameter conditions, reaching tens of milliseconds. This lifetime of atomic cat states is ultimately limited to several seconds by extremely weak spin relaxation and thermal noise. Our work opens up a new way toward the long-standing goal of generating large-size and long-lived cat states, with immediate interests both in fundamental studies and noise-immune quantum technologies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We propose to create and stabilize long-lived macroscopic quantum superposition states in atomic ensembles. We show that using a fully quantum parametric amplifier can cause the simultaneous decay of two atoms and, in turn, create stabilized atomic Schrödinger cat states. Remarkably, even with modest parameters these intracavity atomic cat states can have an extremely long lifetime, up to 4 orders of magnitude longer than that of intracavity photonic cat states under the same parameter conditions, reaching tens of milliseconds. This lifetime of atomic cat states is ultimately limited to several seconds by extremely weak spin relaxation and thermal noise. Our work opens up a new way toward the long-standing goal of generating large-size and long-lived cat states, with immediate interests both in fundamental studies and noise-immune quantum technologies. Close https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.127.093602 doi:10.1103/PhysRevLett.127.093602 Close
4.	Pontus Laurell, Allen Scheie, Chiron J Mukherjee, Michael M Koza, Mechtild Enderle, Zbigniew Tylczyński, Satoshi Okamoto, Radu Coldea, Alan D Tennant, Gonzalo Alvarez Quantifying and Controlling Entanglement in the Quantum Magnet Cs2CoCl4 Phys. Rev. Lett., 127 , pp. 037201, 2021. Abstract \| Links \| BibTeX @article{PhysRevLett.127.037201, title = {Quantifying and Controlling Entanglement in the Quantum Magnet Cs2CoCl4}, author = {Pontus Laurell and Allen Scheie and Chiron J Mukherjee and Michael M Koza and Mechtild Enderle and Zbigniew Tylczyński and Satoshi Okamoto and Radu Coldea and Alan D Tennant and Gonzalo Alvarez}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.127.037201}, doi = {10.1103/PhysRevLett.127.037201}, year = {2021}, date = {2021-07-13}, journal = {Phys. Rev. Lett.}, volume = {127}, pages = {037201}, publisher = {American Physical Society}, abstract = {The lack of methods to experimentally detect and quantify entanglement in quantum matter impedes our ability to identify materials hosting highly entangled phases, such as quantum spin liquids. We thus investigate the feasibility of using inelastic neutron scattering (INS) to implement a model-independent measurement protocol for entanglement based on three entanglement witnesses: one-tangle, two-tangle, and quantum Fisher information (QFI). We perform high-resolution INS measurements on Cs2CoCl4, a close realization of the S=1/2 transverse-field XXZ spin chain, where we can control entanglement using the magnetic field, and compare with density-matrix renormalization group calculations for validation. The three witnesses allow us to infer entanglement properties and make deductions about the quantum state in the material. We find QFI to be a particularly robust experimental probe of entanglement, whereas the one and two-tangles require more careful analysis. Our results lay the foundation for a general entanglement detection protocol for quantum spin systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The lack of methods to experimentally detect and quantify entanglement in quantum matter impedes our ability to identify materials hosting highly entangled phases, such as quantum spin liquids. We thus investigate the feasibility of using inelastic neutron scattering (INS) to implement a model-independent measurement protocol for entanglement based on three entanglement witnesses: one-tangle, two-tangle, and quantum Fisher information (QFI). We perform high-resolution INS measurements on Cs2CoCl4, a close realization of the S=1/2 transverse-field XXZ spin chain, where we can control entanglement using the magnetic field, and compare with density-matrix renormalization group calculations for validation. The three witnesses allow us to infer entanglement properties and make deductions about the quantum state in the material. We find QFI to be a particularly robust experimental probe of entanglement, whereas the one and two-tangles require more careful analysis. Our results lay the foundation for a general entanglement detection protocol for quantum spin systems. Close https://link.aps.org/doi/10.1103/PhysRevLett.127.037201 doi:10.1103/PhysRevLett.127.037201 Close
3.	Nick Träger, Paweł Gruszecki, Filip Lisiecki, Felix Groß, Johannes Förster, Markus Weigand, Hubert Głowiński, Piotr Kuświk, Janusz Dubowik, Gisela Schütz, Maciej Krawczyk, Joachim Gräfe Real-Space Observation of Magnon Interaction with Driven Space-Time Crystals Phys. Rev. Lett., 126 , pp. 057201, 2021. Abstract \| Links \| BibTeX @article{PhysRevLett.126.057201, title = {Real-Space Observation of Magnon Interaction with Driven Space-Time Crystals}, author = {Nick Träger and Paweł Gruszecki and Filip Lisiecki and Felix Groß and Johannes Förster and Markus Weigand and Hubert Głowiński and Piotr Kuświk and Janusz Dubowik and Gisela Schütz and Maciej Krawczyk and Joachim Gräfe}, url = {https://doi.org/10.1103/PhysRevLett.126.057201}, doi = {10.1103/PhysRevLett.126.057201}, year = {2021}, date = {2021-02-03}, journal = {Phys. Rev. Lett.}, volume = {126}, pages = {057201}, abstract = {The concept of space-time crystals (STC), i.e., translational symmetry breaking in time and space, was recently proposed and experimentally demonstrated for quantum systems. Here, we transfer this concept to magnons and experimentally demonstrate a driven STC at room temperature. The STC is realized by strong homogeneous microwave pumping of a micron-sized permalloy (Py) stripe and is directly imaged by scanning transmission x-ray microscopy (STXM). For a fundamental understanding of the formation of the STC, micromagnetic simulations are carefully adapted to model the experimental findings. Beyond the mere generation of a STC, we observe the formation of a magnonic band structure due to back folding of modes at the STC’s Brillouin zone boundaries. We show interactions of magnons with the STC that appear as lattice scattering, which results in the generation of ultrashort spin waves (SW) down to 100-nm wavelengths that cannot be described by classical dispersion relations for linear SW excitation. We expect that room-temperature STCs will be useful to investigate nonlinear wave physics, as they can be easily generated and manipulated to control their spatial and temporal band structures.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The concept of space-time crystals (STC), i.e., translational symmetry breaking in time and space, was recently proposed and experimentally demonstrated for quantum systems. Here, we transfer this concept to magnons and experimentally demonstrate a driven STC at room temperature. The STC is realized by strong homogeneous microwave pumping of a micron-sized permalloy (Py) stripe and is directly imaged by scanning transmission x-ray microscopy (STXM). For a fundamental understanding of the formation of the STC, micromagnetic simulations are carefully adapted to model the experimental findings. Beyond the mere generation of a STC, we observe the formation of a magnonic band structure due to back folding of modes at the STC’s Brillouin zone boundaries. We show interactions of magnons with the STC that appear as lattice scattering, which results in the generation of ultrashort spin waves (SW) down to 100-nm wavelengths that cannot be described by classical dispersion relations for linear SW excitation. We expect that room-temperature STCs will be useful to investigate nonlinear wave physics, as they can be easily generated and manipulated to control their spatial and temporal band structures. Close https://doi.org/10.1103/PhysRevLett.126.057201 doi:10.1103/PhysRevLett.126.057201 Close
2.	Ye-Hong Chen, Wei Qin, Xin Wang, Adam Miranowicz, Franco Nori Shortcuts to Adiabaticity for the Quantum Rabi Model: Efficient Generation of Giant Entangled Cat States via Parametric Amplification Phys. Rev. Lett., 126 , pp. 023602, 2021. Abstract \| Links \| BibTeX @article{PhysRevLett.126.023602, title = {Shortcuts to Adiabaticity for the Quantum Rabi Model: Efficient Generation of Giant Entangled Cat States via Parametric Amplification}, author = {Ye-Hong Chen and Wei Qin and Xin Wang and Adam Miranowicz and Franco Nori}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.126.023602}, doi = {10.1103/PhysRevLett.126.023602}, year = {2021}, date = {2021-01-14}, journal = {Phys. Rev. Lett.}, volume = {126}, pages = {023602}, publisher = {American Physical Society}, abstract = {We propose a method for the fast generation of nonclassical ground states of the Rabi model in the ultrastrong and deep-strong coupling regimes via the shortcuts-to-adiabatic (STA) dynamics. The time-dependent quantum Rabi model is simulated by applying parametric amplification to the Jaynes-Cummings model. Using experimentally feasible parametric drive, this STA protocol can generate large-size Schrödinger cat states, through a process that is ∼10 times faster compared to adiabatic protocols. Such fast evolution increases the robustness of our protocol against dissipation. Our method enables one to freely design the parametric drive, so that the target state can be generated in the lab frame. A largely detuned light-matter coupling makes the protocol robust against imperfections of the operation times in experiments.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We propose a method for the fast generation of nonclassical ground states of the Rabi model in the ultrastrong and deep-strong coupling regimes via the shortcuts-to-adiabatic (STA) dynamics. The time-dependent quantum Rabi model is simulated by applying parametric amplification to the Jaynes-Cummings model. Using experimentally feasible parametric drive, this STA protocol can generate large-size Schrödinger cat states, through a process that is ∼10 times faster compared to adiabatic protocols. Such fast evolution increases the robustness of our protocol against dissipation. Our method enables one to freely design the parametric drive, so that the target state can be generated in the lab frame. A largely detuned light-matter coupling makes the protocol robust against imperfections of the operation times in experiments. Close https://link.aps.org/doi/10.1103/PhysRevLett.126.023602 doi:10.1103/PhysRevLett.126.023602 Close
1.	Nandan K. P. Babu, Aleksandra Trzaskowska, Piotr Graczyk, Grzegorz Centała, Szymon Mieszczak, Hubert Głowiński, Miłosz Zdunek, Sławomir Mielcarek, Jarosław W. Kłos The Interaction between Surface Acoustic Waves and Spin Waves: The Role of Anisotropy and Spatial Profiles of the Modes Nano Lett., 21 (2), pp. 946-951, 2021. Abstract \| Links \| BibTeX @article{doi:10.1021/acs.nanolett.0c03692, title = {The Interaction between Surface Acoustic Waves and Spin Waves: The Role of Anisotropy and Spatial Profiles of the Modes}, author = {Nandan K. P. Babu and Aleksandra Trzaskowska and Piotr Graczyk and Grzegorz Centała and Szymon Mieszczak and Hubert Głowiński and Miłosz Zdunek and Sławomir Mielcarek and Jarosław W. Kłos}, url = {https://doi.org/10.1021/acs.nanolett.0c03692}, doi = {10.1021/acs.nanolett.0c03692}, year = {2021}, date = {2021-01-01}, journal = {Nano Lett.}, volume = {21}, number = {2}, pages = {946-951}, abstract = {The interaction between different types of wave excitation in hybrid systems is usually anisotropic. Magnetoelastic coupling between surface acoustic waves and spin waves strongly depends on the direction of the external magnetic field. However, in the present study we observe that even if the orientation of the field is supportive for the coupling, the magnetoelastic interaction can be significantly reduced for surface acoustic waves with a particular profile in the direction normal to the surface at distances much smaller than the wavelength. We use Brillouin light scattering for the investigation of thermally excited phonons and magnons in a magnetostrictive CoFeB/Au multilayer deposited on a Si substrate. The experimental data are interpreted on the basis of a linearized model of interaction between surface acoustic waves and spin waves.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The interaction between different types of wave excitation in hybrid systems is usually anisotropic. Magnetoelastic coupling between surface acoustic waves and spin waves strongly depends on the direction of the external magnetic field. However, in the present study we observe that even if the orientation of the field is supportive for the coupling, the magnetoelastic interaction can be significantly reduced for surface acoustic waves with a particular profile in the direction normal to the surface at distances much smaller than the wavelength. We use Brillouin light scattering for the investigation of thermally excited phonons and magnons in a magnetostrictive CoFeB/Au multilayer deposited on a Si substrate. The experimental data are interpreted on the basis of a linearized model of interaction between surface acoustic waves and spin waves. Close https://doi.org/10.1021/acs.nanolett.0c03692 doi:10.1021/acs.nanolett.0c03692 Close

Featured publications

2026

2025

2024

2023

2022

2021