Article
Optics
Roohollah Ghobadi
Summary: This study investigates the role of nonclassical kernels in data distribution and parameter estimation, as well as the impact of imperfect state preparation, highlighting the importance of phase-space correlation functions in understanding the distinction between classical machine learning and quantum machine learning.
Article
Physics, Multidisciplinary
Long Tian, Shao-Ping Shi, Yu-Hang Tian, Ya-Jun Wang, Yao-Hui Zheng, Kun-Chi Peng
Summary: Through one type-0 phase-matching optical parametric amplification (OPA) and two subsequent ring filter cavities (RFCs), we successfully demonstrate the generation and detection of two types of continuous variable nonclassical states. By actively stabilizing all degrees of freedom, including filter cavities and relative phases, we achieve squeezed states and Einstein-Podolsky-Rosen entangled states with noise variances significantly below the shot noise limit.
FRONTIERS OF PHYSICS
(2021)
Article
Physics, Multidisciplinary
Martin Gaerttner, Tobias Haas, Johannes Noll
Summary: We present a general class of entanglement criteria for continuous variable systems based on the Husimi Q distribution, which allows for optimization over a set of concave functions. Our criteria have clear advantages under typical experimental constraints and can detect entanglement states that are undetectable by commonly used criteria.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Jing Dong, Tao Wang, Zhuxuan He, Yueer Shi, Lang Li, Peng Huang, Guihua Zeng
Summary: This study proposes a noise-suppression scheme based on carrier frequency switching to mitigate the influence of large-power random noise in quantum-classical co-transmissions. By shifting the transmission signal frequency spectrum and utilizing a digital filter, the excess noise can be reduced and the secret key rate can be increased.
Article
Optics
V. S. Kovtoniuk, I. S. Yeremenko, S. Ryl, W. Vogel, A. A. Semenov
Summary: This article analyzes the nonclassical correlations between outcomes of measurements conducted on two spatial radiation modes, and proves the relationship between these correlations and Bell nonlocality. It also presents a formula for Bell inequalities applicable to continuous variables. The results are illustrated with examples.
Article
Optics
Olena Kovalenko, Vladyslav C. Usenko, Radim Filip
Summary: Two-mode squeezed states are scalable and robust entanglement resources for quantum information protocols;
Optimizing initial squeezing, relative phase, and linear coupling can reduce the degradation of Gaussian entanglement in the presence of crosstalk;
Compensating crosstalk through mode interference improves the efficiency of using multimode continuous-variable photonic entanglement in quantum networks.
Article
Optics
Qingwei Wang, Yajun Wang, Xiaocong Sun, Yuhang Tian, Wei Li, Long Tian, Xudong Yu, Jing Zhang, Yaohui Zheng
Summary: A universal scheme of a continuous variable quantum state distributor that performs point-to-multipoint distributions via quantum teleportation with partially disembodied transport is presented. Controllable distributions were demonstrated by manipulating the squeezing factor of EPR entanglement, leading to gradual changes in the fidelities of the receivers.
Article
Physics, Mathematical
Giovanni Ferrari, Ludovico Lami, Thomas Theurer, Martin B. Plenio
Summary: In this study, we examine asymptotic state transformations in continuous variable quantum resource theories. We prove that lower semicontinuity and strong superadditivity can be used to bound asymptotic transformation rates in these settings. We provide applications to optical nonclassicality, entanglement, and quantum thermodynamics resource theories. Our findings offer computable upper bounds for asymptotic transformation rates, including those achievable with linear optical elements.
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2023)
Article
Optics
Shaoping Shi, Yajun Wang, Long Tian, Wei Li, Yimiao Wu, Qingwei Wang, Yaohui Zheng, Kunchi Peng
Summary: This article presents a fully connected continuous-variable quantum teleportation network architecture, where a squeezed state of light distributes entangled sideband modes to each communication link, offering potential for various tasks of quantum information processing.
LASER & PHOTONICS REVIEWS
(2023)
Article
Physics, Multidisciplinary
Ya-Dong Wu, Ge Bai, Giulio Chiribella, Nana Liu
Summary: Continuous-variable quantum information, encoded into infinite-dimensional quantum systems, is a promising platform for many quantum information protocols. It is essential to have reliable protocols for verifying multimode continuous-variable entangled states and devices, particularly in realistic scenarios where identical and independent operations cannot be guaranteed. This letter proposes the first set of protocols for verifying such states and devices in non-i.i.d scenarios, applicable to various types of quantum states and operations.
PHYSICAL REVIEW LETTERS
(2021)
Article
Quantum Science & Technology
Wenchao Ge, Kurt Jacobs, M. Suhail Zubairy
Summary: It is well-known that the precision of phase measurement using a Mach-Zehnder interferometer can be greatly enhanced by adding weak nonclassical light. This enhancement, termed 'metrological power', has previously only been calculated for specific measurement configurations. However, this study optimizes over all configurations to determine the maximum enhancement achievable by any nonclassical state together with strong classical states, providing a unified quantification of metrological power.
NPJ QUANTUM INFORMATION
(2023)
Article
Physics, Multidisciplinary
V Roman-Rodriguez, B. Brecht, K. Srinivasan, C. Silberhorn, N. Treps, E. Diamanti, V Parigi
Summary: Configurable and scalable continuous variable quantum networks for measurement-based quantum information protocols can be obtained via parametric down conversion in non-linear waveguides, with the use of symmetric group velocity matching. By identifying type II PDC in a single waveguide as the best suited process, multiple modes with non-negligible amount of squeezing can be obtained, paving the way toward large-scale quantum networks in the CV regime.
NEW JOURNAL OF PHYSICS
(2021)
Article
Physics, Multidisciplinary
Ivan Derkach, Vladyslav C. Usenko
Summary: The study shows that achieving quantum key distribution over satellite channels requires stable setup and reduction of noise and loss, with the key extraction method significantly affecting protocol robustness. Optimized signal squeezing can substantially improve protocol applicability, reducing system clock rates and aperture sizes compared to coherent-state protocols.
Article
Physics, Multidisciplinary
Dan-Bo Zhang, Guo-Qing Zhang, Zheng-Yuan Xue, Shi-Liang Zhu, Z. D. Wang
Summary: The article introduces a quantum algorithm assisted with continuous variables for simulating quantum systems at finite temperatures, with time complexity polynomially scaling with inverse temperature and desired accuracy. Demonstrating the algorithm by simulating finite temperature phase diagrams of quantum Ising and Kitaev models, it shows that important crossover phase diagrams of the Kitaev ring can be accurately simulated by quantum computers with only a few qubits, making the algorithm implementable on current quantum processors. Additionally, a protocol utilizing superconducting or trapped ion quantum computers is proposed.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Bartosz Regula, Ludovico Lami, Giovanni Ferrari, Ryuji Takagi
Summary: The study introduces a general method for quantifying resources for continuous-variable quantum systems based on robustness measure, with a direct operational interpretation. It is shown to be a well-behaved resource quantifier applicable to various physically relevant resources, such as optical nonclassicality.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Vladyslav C. Usenko, Radim Filip
Article
Optics
Lukas Lachman, Radim Filip
Article
Optics
Pavel Zemanek, Martin Siler, Oto Brzobohaty, Petr Jakl, Radim Filip
Article
Optics
Radim Filip, Pavel Zemanek
Article
Multidisciplinary Sciences
Lukas Lachman, Lukas Slodicka, Radim Filip
SCIENTIFIC REPORTS
(2016)
Article
Multidisciplinary Sciences
Laszlo Ruppert, Radim Filip
SCIENTIFIC REPORTS
(2017)
Proceedings Paper
Optics
Martin Siler, Petr Jakl, Radim Filip, Artem Ryabov, Pavel Zemanek
20TH SLOVAK-CZECH-POLISH OPTICAL CONFERENCE ON WAVE AND QUANTUM ASPECTS OF CONTEMPORARY OPTICS
(2016)
Article
Optics
Kimin Park, Petr Marek, Radim Filip
Article
Optics
Nikita Vostrosablin, Andrey A. Rakhubovsky, Radim Filip
Article
Physics, Fluids & Plasmas
Artem Ryabov, Pavel Zemanek, Radim Filip
Article
Optics
Petr Marek, Lukas Lachman, Lukas Slodicka, Radim Filip
Article
Optics
Kimin Park, Petr Marek, Radim Filip
Article
Optics
Laszlo Ruppert, Vladyslav C. Usenko, Radim Filip
Article
Optics
Timur Sh. Iskhakov, Vladyslav C. Usenko, Radim Filip, Maria V. Chekhova, Gerd Leuchs
Article
Optics
Andrey A. Rakhubovsky, Nikita Vostrosablin, Radim Filip