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Quantum precision measurement of two-dimensional forces with 10^(-28)-Newton stability

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Science Bulletin 2022年第22期67卷 2291-2297页

作者： Xinxin Guo Zhongcheng Yu Fansu Wei Shengjie Jin Xuzong Chen Xiaopeng Li Xibo Zhang Xiaoji Zhou State Key Laboratory of Advanced Optical Communication System and Network School of ElectronicsPeking UniversityBeijing 100871China State Key Laboratory of Surface Physics Key Laboratory of Micro and Nano Photonic Structures(MOE)and Department of PhysicsFudan UniversityShanghai 200433China Institute for Nanoelectronic Devices and Quantum Computing Fudan UniversityShanghai 200433China Shanghai Qi Zhi Institute AI TowerXuhui DistrictShanghai 200232China Shanghai Research Center for Quantum Sciences Shanghai 201315China International Center for Quantum Materials School of PhysicsPeking UniversityBeijing 100871China Institute of Advanced Functional Materials and Devices Shanxi UniversityTaiyuan 030031China

High-precision sensing of vectorial forces has broad impact on both fundamental research and technological applications such as the examination of vacuum fluctuations and the detection of surface roughness of *** years have witnessed much progress on sensing alternating electromagnetic forces for the rapidly advancing quantum technology-orders of magnitude improvement has been accomplished on the detection sensitivity with atomic sensors,whereas such high-precision measurements for static electromagnetic forces have rarely been ***,based on quantum atomic matter waves confined by a two-dimensional optical lattice,we perform precision measurement of static electromagnetic forces by imaging coherent wave mechanics in the reciprocal *** lattice confinement causes a decoupling between real-space and reciprocal dynamics,and provides a rigid coordinate frame for calibrating the wavevector accumulation of the matter *** that we achieve a stateof-the-art sensitivity of 2.30(8)×10^(-26) N/√***-term stabilities on the order of 10^(-28) N are observed in the two spatial components of a force,which allows probing atomic Van der Waals forces at one millimeter *** a further illustrative application,we use our atomic sensor to calibrate the control precision of an alternating electromagnetic force applied in the *** developments of this method hold promise for delivering unprecedented atom-based quantum force sensing technologies.

关键词： Quantum precision measurement Bose–Einstein condensates optical lattices Ultracold atoms Force sensor

Implementation of a double-path multi-mode interferometer using spinor BEC

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arXiv 2019年

作者： Tang, Pengju Dong, Xiangyu Zhang, Wenjun Li, Yunhong Chen, Xuzong Zhou, Xiaoji State Key Laboratory of Advanced Optical Communication System and Network Department of Electronics Peking University Beijing100871 China School of Electronics and information Xi’an Polytechnic University Xi’an710048 China Collaborative Innovation Center of Extreme Optics Shanxi University Shanxi Taiyuan030006 China

We realize a double-path multi-mode matter wave interferometer with spinor Bose-Einstein condensate (BEC) and observe clear spatial interference fringes as well as a periodic change of the visibility in the time domain, which we refer to as the time domain interference and is different from the traditional double-path interferometer. By changing the relative phase of the two paths, we find that the spatial fringes first lose coherence and recover. As the number of modes increases, the time domain interference signal with the narrower peaks is observed, which is beneficial to the improvement of the resolution of the phase measurement. We also investigated the influence of initial phase configuration and phase evolution rate between different modes in the two paths. With enhanced resolution, the sensitivity of interferometric measurements of physical observables can also be improved by properly assigning measurable quantities to the relative phase between two paths. Copyright © 2019, The Authors. All rights reserved.

关键词： Bose-Einstein condensation

Atomic transport dynamics in crossed optical dipole trap

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arXiv 2024年

作者： Peng, Peng Zhang, Zhengxi Fan, Yaoyuan Yin, Guoling Mao, Dekai Chen, Xuzong Xiong, Wei Zhou, Xiaoji State Key Laboratory of Advanced Optical Communication System and Network School of Electronics Peking University Beijing100871 China Institute of Carbon-based Thin Film Electronics Peking University Taiyuan Shanxi030012 China State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-Electronics Shanxi University Taiyuan030006 China

We study the dynamical evolution of cold atoms in crossed optical dipole trap theoretically and experimentally. The atomic transport process is accompanied by two competitive kinds of physical mechanics, atomic loading and atomic loss. The loading process normally is negligible in the evaporative cooling experiment on the ground, while it is significant in the preparation of ultra-cold atoms in the space station. Normally, the atomic loading process is much weaker than the atomic loss process, and the atomic number in the center region of the trap decreases monotonically, as reported in previous research. However, when the atomic loading process is comparable to the atomic loss process, the atomic number in the center region of the trap will initially increase to a maximum value and then slowly decrease, and we have observed the phenomenon first. The increase of atomic number in the center region of the trap shows the presence of the loading process, and this will be significant especially under microgravity conditions. We build a theoretical model to analyze the competitive relationship, which coincides with the experimental results well. Furthermore, we have also given the predicted evolutionary behaviors under different conditions. This research provides a solid foundation for further understanding of the atomic transport process in traps. The analysis of loading process is of significant importance for the preparation of ultra-cold atoms in a crossed optical dipole trap under microgravity conditions. © 2024, CC BY.

关键词： Space stations

Discovering Mass Activities Using Anomalies in Individual Mobility Motifs

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Discovering Mass Activities Using Anomalies in Individual Mo...

Symposia and Workshops on Ubiquitous, Autonomic and Trusted Computing, UIC-ATC

作者： Zhenhuan Li Haiyang Wang Xiaming Chen Yongkun Wang Yaohui Jin Wenjun Zhang Inst. of Image Commun. & Inf. Process. Shanghai Jiao Tong University P. R. China State Key Lab of Advanced Optical Communication System and Network Shanghai Jiao Tong University P. R. China Network and Information Center Shanghai Jiao Tong University P. R. China

Mobility motif is a typical topology structure shared by movement trajectories, which could exhibit multi-scale spatio-temporal patterns in human behavior. There are two types of motifs, frequent, infrequent. The infrequent one hasn't got enough attention in research. In this paper, we study the relationship between infrequent motifs, mass activities. We have discovered that crowds are more likely to generate abnormal motifs when they attend activities than on ordinary days. Inspired by the discovery, we propose a novel model to incorporate the connection between motif anomalies, mass activities, which is verified by our real-world data driven analysis. Compared to previous mobility analysis, our work facilitates the inspection of human mobility anomalies in a fresh perspective, it is a promising step towards unraveling the actual causation behind human mobility.

关键词： Buildings Trajectory IEEE 802.11 Standard Data mining Global Positioning system Internet Topology

Realizing a spatially correlated lattice interferometer

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arXiv 2024年

作者： Peng, Peng Mao, Dekai Liang, Yi Yin, Guoling Shui, Hongmian Song, Bo Zhou, Xiaoji State Key Laboratory of Advanced Optical Communication System and Network School of Electronics Peking University Beijing100871 China State Key Laboratory for Mesoscopic Physics Frontiers Science Center for Nano-Optoelectronics School of Physics Peking University Beijing100871 China Institute of Carbon-Based Thin Film Electronics Peking University Shanxi Taiyuan030012 China

Atom interferometers provide a powerful tool for measuring physical constants and testifying fundamental physics with unprecedented precision. Conventional atom interferometry focuses on the phase difference between two paths and utilizes matter waves with fixed coherence. Here, we report on realizing a Ramsey-Bordé interferometer of coherent matter waves dressed by a moving optical lattice in the gravity direction, and explore the resulting interference along multiple paths with tunable coherence. We investigate spatial correlations of atoms both within the lattice and between two arms by interferometry, and observe the emerging multiple interference peaks owing to the long-range coherence nature of the Bose-Einstein condensate. Our findings agree well with theoretical simulations, paving the way for high-precision interferometry with ultracold atoms. © 2024, CC BY.

关键词： Interferometers

Parallel multicomponent interferometer with a spinor Bose-Einstein condensate

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arXiv 2018年

作者： Tang, Pengju Peng, Peng Li, Zhihan Chen, Xuzong Li, Xiaopeng Zhou, Xiaoji State Key Laboratory of Advanced Optical Communication System and Network Department of Electronics Peking University Beijing100871 China State Key Laboratory of Surface Physics Institute of Nano-electronics and Quantum Computing Department of Physics Fudan University Shanghai200433 China Collaborative Innovation Center of Advanced Microstructures Nanjing210093 China Collaborative Innovation Center of Extreme Optics Shanxi University Taiyuan Shanxi030006 China

Atom interferometry with high visibility is of high demand for precision measurements. Here, a parallel multicomponent interferometer is achieved by preparing a spin-2 Bose-Einstein condensate of 87Rb atoms confined in a hybrid magneto-optical trap. After the preparation of a spinor Bose-Einstein condensate with spin degrees of freedom entangled, we observe four spatial interference patterns in each run of measurements corresponding to four hyperfine states we mainly populate in the experiment. The atomic populations in different Zeeman sublevels are made controllably using magnetic-field-pulse induced Majorana transitions. The spatial separation of atom cloud in different hyperfine states is reached by Stern-Gerlach momentum splitting. The high visibility of the interference fringes is reached by designing a proper overlap of the interfering wave packets. Due to uncontrollable phase accumulation in Majorana transitions, the phase of each individual spin is found to be subjected to unreproducible shift in multiple experimental runs. However, the relative phase across different spins is stable, paving a way towards noise-resilient multicomponent parallel interferometers. Copyright © 2018, The Authors. All rights reserved.

关键词： Interferometers

Dynamical emergence of a potts-nematic superfluid in a hexagonal sp2 optical lattice

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arXiv 2019年

作者： Jin, Shengjie Zhang, Wenjun Guo, Xinxin Chen, Xuzong Zhou, Xiaoji Li, Xiaopeng State Key Laboratory of Advanced Optical Communication System and Network Department of Electronics Peking University Beijing100871 China Collaborative Innovation Center of Extreme Optics Shanxi University Taiyuan Shanxi030006 China State Key Laboratory of Surface Physics Institute of Nanoelectronics and Quantum Computing Department of Physics Fudan University Shanghai200433 China Collaborative Innovation Center of Advanced Microstructures Nanjing210093 China

Nematicity is a long-range orientational order associated with rotation-symmetry breaking in the presence of translational invariance, borne out of the description of classical liquid crystals (1). This order also emerges in interacting electrons and has been found to largely intertwine with multi-orbital correlation in high-temperature superconductivity, where Ising nematicity arises from a four-fold rotation symmetry C4 brokendown to C2 (2, 3). Here we report an observation of a bosonic superfluid with a three-state (Z3) quantum nematic order, dubbed "Potts-nematicity", in a system of ultracold atoms loaded in an excited band of a hexagonal optical lattice described by an sp2-orbital hybridized model (4, 5). This Potts-nematic superfluid spontaneously breaks a three-fold rotation symmetry of the lattice, qualitatively distinct from the Ising nematicity. Our field theory analysis shows that the Potts-nematic order is stabilized by intricate renormalization effects enabled by strong inter-orbital mixing present in the hexagonal lattice. This discovery paves a way to investigate quantum vestigial orders (6) in multi-orbital atomic superfluids. Copyright © 2019, The Authors. All rights reserved.

关键词： Crystal lattices

A hybrid-integrated external cavity laser with ultra-wide wavelength tuning range and high side-mode suppression

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A hybrid-integrated external cavity laser with ultra-wide wa...

optical Fiber communication (OFC) Conference

作者： Yuyao Guo Xinhang Li Weihan Xu Chuxin Liu Minhui Jin Liangjun Lu Jingya Xie Anton Stroganov Jianping Chen Linjie Zhou State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Institute for Advanced Communication and Data Science Shanghai Jiao Tong University Shanghai China SJTU-Pinghu Institute of Intelligent Optoelectronics Pinghu China Terahertz Technology Innovation Research Institute Terahertz Spectrum and Imaging Technology Cooperative Innovation Center Shanghai Key Lab of Modern Optical System University of Shanghai for Science and Technology Shanghai China LIGENTEC SA EPFL Innovation Park Bâtiment L Ecublens Switzerland

We present a III-V/Si 3 N 4 hybrid-integrated tunable laser. The laser shows a record of ~170-nm tuning range with a side mode suppression ratio above 64 dB and an intrinsic linewidth below 2.8 kHz. © 2022 The A... 详细信息

ISBN: (纸本)9781557524669

关键词： Performance evaluation Couplings Laser modes Optics optical fiber communication Broadband communication Laser tuning

Atom-Orbital Qubit under Holonomic Quantum Control

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arXiv 2021年

作者： Shui, Hongmian Jin, Shengjie Li, Zhihan Wei, Fansu Chen, Xuzong Li, Xiaopeng Zhou, Xiaoji State Key Laboratory of Advanced Optical Communication System and Network Department of Electronics Peking University Beijing100871 China State Key Laboratory of Surface Physics Institute of Nanoelectronics and Quantum Computing Department of Physics Fudan University Shanghai 200438 China Shanghai Qi Zhi Institute Shanghai 200030 China Collaborative Innovation Center of Extreme Optics Shanxi University Shanxi Taiyuan030006 China

Quantum computing has been attracting tremendous efforts in recent years. One prominent application is to perform programmable quantum simulations of electron correlations in large molecules and solid-state materials, where orbital degrees of freedom are crucial to quantitatively model electronic properties. Electron orbitals unlike quantum spins obey crystal symmetries, making the atomic orbital in optical lattices a natural candidate to emulate electron orbitals. Here, we construct an atom-orbital qubit by manipulating s- and d-orbitals of atomic Bose-Einstein condensation in an optical lattice. Noise-resilient single-qubit gates are achieved by performing holonomic quantum control, which admits geometrical protection. We find it is critical to eliminate the orbital leakage error in the system. Our work opens up wide opportunities for atom-orbital based quantum information processing, of vital importance to programmable quantum simulations of multi-orbital physics in molecules and quantum materials. © 2021, CC BY.

关键词： Atoms