Article
Optics
Y. Chew, T. Tomita, T. P. Mahesh, S. Sugawa, S. de Leseleuc, K. Ohmori
Summary: Rydberg atoms show promise for ultrafast quantum operations, but strong interactions between single atoms have been challenging to harness. The authors introduce novel techniques to trap and cool atoms, and use laser pulses to excite them to a Rydberg state. Ultrafast energy exchange and conditional phase are observed.
Article
Optics
Wen-Hao Zhou, Zhi-Qiang Jiao, Hang Li, Jun Gao, Xiao-Wei Wang, Ruo-Jing Ren, Xiao-Yun Xu, Lu-Feng Qiao, Xian-Min Jin
Summary: Researchers propose and experimentally demonstrate heralded multipartite entanglements on a three-dimensional photonic chip. By controlling the coherent evolution of a single photon in multiple spatial modes, they dynamically tune the high-order W-states of different orders in a single photonic chip. Using an effective witness, they observe and verify 61-partite quantum entanglements in a 121-site photonic lattice. These results offer insights into the accessible size of quantum entanglements and may advance large-scale quantum information processing applications.
Article
Optics
Xinhui Li, Yukun Wang, Yunguang Han, Shi-Ning Zhu
Summary: In this study, we investigate which states can be self-tested with the same measurement settings by using fixed two-binary measurements. By analyzing the structure of generalized tilted-Clauser-Horne-Shimony-Holt Bell operators with the sum-of-squares decomposition method, we demonstrate that a specific class of two-qubit entangled states can be self-tested with the same measurement settings. The robustness analysis confirms the feasibility of our scheme for practical experiment instruments, and the results have potential applications in various quantum information processing tasks.
Article
Multidisciplinary Sciences
Avikar Periwal, Eric S. Cooper, Philipp Kunkel, Julian F. Wienand, Emily J. Davis, Monika Schleier-Smith
Summary: Interactions play a crucial role in controlling the flow of information and creating correlations in many-body quantum systems. By programming non-local interactions in an array of atomic ensembles within an optical cavity, researchers have been able to access effective geometries with different dimensions and topologies than the physical geometry of the array. This work has implications for simulating frustrated magnets, investigating quantum optimization paradigms, and engineering entangled resource states for sensing and computation.
Article
Optics
Rui Qu, Yunlong Wang, Xiaolin Zhang, Shihao Ru, Feiran Wang, Hong Gao, Fuli Li, Pei Zhang
Summary: The article presents a more robust method for certifying genuine high-dimensional quantum steering in noisy environments, surpassing previous restrictions and demonstrating its practicality through experimental demonstrations.
Article
Physics, Multidisciplinary
Daipengwei Bao, Xiaoqing Tan, Qingshan Xu, Haozhen Wang, Rui Huang
Summary: In this paper, a method for self-testing four-qubit symmetric states is proposed, and the robustness analysis is conducted based on vector norm inequalities. The authors generalize this idea to a parameterized family of four-qubit symmetric states.
Article
Optics
Sebastien Designolle
Summary: Quantum systems of high dimensions have interesting properties in observing entanglement or other forms of correlations, making them attractive for experiments in quantum communication or quantum cryptography due to their improved resistance to noise. However, verifying the high-dimensional nature remains challenging, especially when weak assumptions are made on the parties involved, such as considering one of them as a black box. Recently, the concept of genuine high-dimensional steering has been introduced, allowing for a one-sided device-independent certification of the dimension of a bipartite shared state using only two measurements. In this study, the author overcomes the limitations by developing universal bounds on the incompatibility robustness for more than two measurements, which can serve as meaningful dimension certificates.
Article
Optics
Akira Matsumura, Yasusada Nambu, Kazuhiro Yamamoto
Summary: In this study, we investigate the violation of the Leggett-Garg inequalities due to gravitational interaction in a hybrid system. We discuss how entanglement affects this violation and also explore the feasibility of detecting such violations in hybrid systems.
Article
Quantum Science & Technology
Senrui Chen, Wenjun Yu, Pei Zeng, Steven T. Flammia
Summary: The study presents an efficient and noise-resilient protocol for learning properties of quantum states, which can effectively characterize and mitigate noise interference in the shadow estimation scheme, suitable for current experimental conditions, with good sampling efficiency and noise resilience.
Article
Optics
Ping Wang, Peng Huang, Rui Chen, Guihua Zeng
Summary: Free-space continuous-variable quantum key distribution (CV-QKD) requires precise frame synchronization, and the fluctuation of channel transmittance increases the difficulty of synchronization. A novel method of inserting synchronization frames has been proposed and tested for feasibility and efficiency.
Article
Physics, Multidisciplinary
Michael Meth, Viacheslav Kuzmin, Rick van Bijnen, Lukas Postler, Roman Stricker, Rainer Blatt, Martin Ringbauer, Thomas Monz, Pietro Silvi, Philipp Schindler
Summary: In this study, a method for implementing quantum-encoded tensor-network (TN) states on an ion-trap quantum computer is proposed, with the ground states of the extended Su-Schrieffer-Heeger model as a case study. The generated states are characterized and verified to possess topological order through estimation of topological invariants.
Article
Optics
Julen S. Pedernales, Martin B. Plenio
Summary: This study designs a method that utilizes spatial correlations to reduce the impact of perturbations from distant sources on the visibility of matter-wave interference patterns, and develops a general framework for correcting the multipole expansion of environmental potential fields. This method works for stochastic field fluctuations at any timescale and does not require quantum correlations.
Article
Physics, Multidisciplinary
Xinhui Li, Yukun Wang, Yunguang Han, Shi-Ning Zhu
Summary: This paper investigates the effects of reduced measurements independence on self-testing, and finds that it allows device providers to control the device and fake quantum behavior.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Quantum Science & Technology
Kishor Bharti, Maharshi Ray, Zhen-Peng Xu, Masahito Hayashi, Leong-Chuan Kwek, Adan Cabello
Summary: This study addresses the problem of self-testing quantum correlations using tools from graph theory. It is found that the set of quantum correlations, BQ, is strictly contained in a set associated with a graph, 0(G), which is easier to characterize. When the optimum values of BQ and 0(G) coincide, self-testing can be demonstrated by proving self-testability with 0(G). This approach also connects self-testing to open problems in discrete mathematics.
Article
Optics
Yong-Guang Zheng, Zi-Hang Zhu, Ying Liu, Wei-Yong Zhang, Han-Yi Wang, Song-Tao Yu, An Luo, Hui Sun, Zhen-Sheng Yuan, Jian-Wei Pan
Summary: This study demonstrates a robust site-resolved addressing method by locking the position of the addressing beam to the optical lattice phase. Through feedback loop and phase-locking, the accuracy and success rate of addressing are significantly improved.
Article
Physics, Multidisciplinary
Jun-Hao Wei, Xin-Yu Xu, Shu-Ming Hu, Qing Zhou, Li Li, Nai-Le Liu, Kai Chen
Summary: Measurement-device-independent quantum key distribution (MDI-QKD) is a method that enables two legitimate users to generate shared information-theoretic secure keys with immunity to all detector side attacks. However, the original proposal using polarization encoding is sensitive to polarization rotations from birefringence and misalignment. To overcome this problem, we propose a robust QKD protocol based on decoherence-free subspaces using polarization-entangled photon pairs. We design a logical Bell state analyzer for such encoding.
Article
Optics
Wei Li, Likang Zhang, Hao Tan, Yichen Lu, Sheng-Kai Liao, Jia Huang, Hao Li, Zhen Wang, Hao-Kun Mao, Bingze Yan, Qiong Li, Yang Liu, Qiang Zhang, Cheng-Zhi Peng, Lixing You, Feihu Xu, Jian-Wei Pan
Summary: This article reports a QKD system that can generate keys at a record high rate of 115.8 Mb/s over a 10 km standard optical fiber and distribute keys over up to 328 km of ultralow-loss fiber. These abilities are attributed to a multipixel superconducting nanowire single-photon detector with an ultrahigh counting rate, an integrated transmitter that can stably encode polarization states with low error, a fast post-processing algorithm for generating keys in real time, and the high system clock rate operation. The results demonstrate the feasibility of practical high-rate QKD with photonic techniques, thus opening its possibility for widespread applications.
Article
Physics, Multidisciplinary
Wei Li, Likang Zhang, Yichen Lu, Zheng-Ping Li, Cong Jiang, Yang Liu, Jia Huang, Hao Li, Zhen Wang, Xiang-Bin Wang, Qiang Zhang, Lixing You, Feihu Xu, Jian-Wei Pan
Summary: We propose and demonstrate a new method to achieve twin-field quantum key distribution (TF-QKD) without the need for phase locking. By separating the communication time into reference frames and quantum frames, we establish a global phase reference using the reference frames and reconcile the phase reference efficiently using a tailored algorithm based on fast Fourier transform. We successfully demonstrate no-phase-locking TF-QKD from short to long distances over standard optical fibers, achieving high secret key rates and repeaterlike key rates. Our work provides a scalable and practical solution to TF-QKD, representing an important step towards its wide applications.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Jian Qin, Yu-Hao Deng, Han-Sen Zhong, Li-Chao Peng, Hao Su, Yi-Han Luo, Jia-Min Xu, Dian Wu, Si-Qiu Gong, Hua-Liang Liu, Hui Wang, Ming-Cheng Chen, Li Li, Nai-Le Liu, Chao-Yang Lu, Jian-Wei Pan
Summary: Quantum metrology aims to enhance measurement sensitivity by utilizing quantum resources. We propose and realize a novel quantum metrology scheme that combines unconventional nonlinear interferometers and stimulated emission of squeezed light. Our method achieves a scalable, unconditional, and robust quantum metrological advantage, outperforming ideal 5-N00N states. The demonstrated enhancement in Fisher information per photon, without discounting for imperfections or photon loss, makes our approach applicable in practical quantum metrology at low photon flux regime.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Xue-Mei Gu, Liang Huang, Alejandro Pozas-Kerstjens, Yang-Fan Jiang, Dian Wu, Bing Bai, Qi-Chao Sun, Ming-Cheng Chen, Jun Zhang, Sixia Yu, Qiang Zhang, Chao-Yang Lu, Jian-Wei Pan
Summary: Nonlocality in networks composed of independent sources exhibits different phenomena compared to standard Bell scenarios. Network nonlocality in the entanglement-swapping scenario has been extensively studied, but previous violations of bilocality inequality could not certify the nonclassicality of their sources. We experimentally observe full network nonlocal correlations in a network where the loopholes of source-independence, locality, and measurement-independence are closed. Our experiment violates known inequalities for nonfull network nonlocal correlations by over 5 standard deviations, confirming the absence of classical sources.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Li-Zheng Liu, Yue-Yang Fei, Yingqiu Mao, Yi Hu, Rui Zhang, Xu-Fei Yin, Xiao Jiang, Li Li, Nai-Le Liu, Feihu Xu, Yu-Ao Chen, Jian-Wei Pan
Summary: In this study, a full-period quantum phase estimation approach is proposed and demonstrated. The approach adopts Kitaev's phase estimation algorithm to eliminate phase ambiguity and uses GHZ states to obtain phase values. Through an eight-photon experiment, the estimation of unknown phases in a full period is achieved, and the phase super-resolution and sensitivity beyond the shot-noise limit are observed. This research provides a new way for quantum sensing and represents a solid step towards its general applications.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Chong Ying, Bin Cheng, Youwei Zhao, He-Liang Huang, Yu-Ning Zhang, Ming Gong, Yulin Wu, Shiyu Wang, Futian Liang, Jin Lin, Yu Xu, Hui Deng, Hao Rong, Cheng-Zhi Peng, Man -Hong Yung, Xiaobo Zhu, Jian-Wei Pan
Summary: Although NISQ quantum computing devices are still limited in terms of qubit quantity and quality, quantum computational advantage has been experimentally demonstrated. Hybrid quantum and classical computing architectures have become the main paradigm for exhibiting NISQ applications, with the use of low-depth quantum circuits. This study demonstrates a circuit-cutting method for simulating quantum circuits with multiple logical qubits using only a few physical superconducting qubits, showcasing higher fidelity and scalability.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Yu-Hao Deng, Si-Qiu Gong, Yi-Chao Gu, Zhi-Jiong Zhang, Hua-Liang Liu, Hao Su, Hao-Yang Tang, Jia-Min Xu, Meng-Hao Jia, Ming-Cheng Chen, Han-Sen Zhong, Hui Wang, Jiarong Yan, Yi Hu, Jia Huang, Wei -Jun Zhang, Hao Li, Xiao Jiang, Lixing You, Zhen Wang, Li Li, Nai-Le Liu, Chao -Yang Lu, Jian-Wei Pan
Summary: Gaussian boson sampling (GBS) is a protocol for demonstrating quantum computational advantage and is mathematically associated with graph-related and quantum chemistry problems. This study investigates the enhancement of GBS over classical stochastic algorithms on noisy quantum devices in the computationally interesting regime. Experimental results show the presence of GBS enhancement with a large photon-click number and robustness under certain noise, which may stimulate the development of more efficient classical and quantum-inspired algorithms.
PHYSICAL REVIEW LETTERS
(2023)
Article
Instruments & Instrumentation
Chao Yu, Tianyi Li, Xian-Song Zhao, Hai Lu, Rong Zhang, Feihu Xu, Jun Zhang, Jian-Wei Pan
Summary: In this study, a 4H-SiC single-photon avalanche diode (SPAD) based free-running ultraviolet single-photon detector (UVSPD) with ultralow afterpulse probability is reported. A beveled mesa structure is designed and fabricated for the 4H-SiC SPAD, which shows the characteristic of ultralow dark current. A readout circuit of passive quenching and active reset with a tunable hold-off time setting is further developed to significantly suppress the afterpulsing effect. The nonuniformity of photon detection efficiency (PDE) across the SPAD active area is investigated for performance optimization. The compact UVSPD shows a PDE of 10.3%, a dark count rate of 133 kcps, and an afterpulse probability of 0.3% at 266 nm, indicating its potential for practical ultraviolet photon-counting applications.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Review
Physics, Multidisciplinary
Nikita M. Kondratiev, Valery E. Lobanov, Artem E. Shitikov, Ramzil R. Galiev, Dmitry A. Chermoshentsev, Nikita Yu. Dmitriev, Andrey N. Danilin, Evgeny A. Lonshakov, Kirill N. Min'kov, Daria M. Sokol, Steevy J. Cordette, Yi-Han Luo, Wei Liang, Junqiu Liu, Igor A. Bilenko
Summary: The stabilization and manipulation of laser frequency using an external cavity is widely used in fundamental research and laser applications. The self-injection locking effect can significantly reduce laser linewidth and noise by locking the laser emission frequency to the cavity mode. This method paves the way for high-performance, compact, and cost-effective semiconductor lasers, and it also enables the generation of both pulse and frequency combs in the same microresonator using integrated photonics technology.
FRONTIERS OF PHYSICS
(2023)
Article
Optics
Zhichao Ye, Haiyan Jia, Zhangjun Huang, Chen Shen, Jinbao Long, Baoqi Shi, Yi-Han Luo, Lan Gao, Wei Sun, Hairun Guo, Jijun He, Junqiu Liu
Summary: The foundry development of integrated photonics has revolutionized optical interconnect and datacenters. Silicon nitride (Si3N4) integrated photonics has become the leading platform for linear and Kerr nonlinear photonics, offering low optical loss and ultra-low noise chip-scale lasers. However, challenges remain in transferring these processes to CMOS foundries operating with larger wafers.
PHOTONICS RESEARCH
(2023)
Article
Optics
Jin Cao, Huan Yang, Zhen Su, Xin-Yao Wang, Jun Rui, Bo Zhao, Jian-Wei Pan
Summary: We have successfully prepared a quantum degenerate mixture of 23Na 40K molecules and 40K atoms. The atoms are highly degenerate with a large number ratio, while the molecules are in a moderately degenerate state. The elastic collisions between the atoms and molecules provide a thermalization mechanism, allowing the molecules to reach thermal equilibrium before significant losses occur. The degeneracy of the molecules is maintained for a sufficient time interval for further study and production of ultracold triatomic molecular gases.
