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Revisit on quantum parameter estimation approach for Mach-Zehnder interferometry

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arXiv 2025年

作者： Hu, Bing-Shu Lu, Xiao-Ming School of Sciences Hangzhou Dianzi University Hangzhou310018 China Zhejiang Key Laboratory of Quantum State Control and Optical Field Manipulation Hangzhou Dianzi University Hangzhou310018 China

The Mach-Zehnder interferometer is a fundamental tool for measuring phase shifts between two light paths, serving as a crucial prototype for achieving high-precision measurements in various scientific and technological applications. In this study, we analyze different models for estimating relative phase shift in a general two-arm Mach-Zehnder interferometer. We demonstrated that single-parameter estimation models can be reduced from the two-parameter estimation model by imposing appropriate constraints on the parameter space. To make quantum Fisher information of the single-parameter estimation models meaningful, the corresponding constraints must be guaranteed in the experiment implementation. Furthermore, we apply the quantum Fisher information approach to analyze the Mach-Zehnder interferometer with the an input state composed of a displaced squeezed vacuum state and a coherent state, providing insights into the precision limits of such configurations. Copyright © 2025, The Authors. All rights reserved.

关键词： Mach-Zehnder interferometers

Optimal Estimation of Temperature

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arXiv 2025年

作者： Zhang, Shaoyong Fei, Zhaoyu Wang, Xiaoguang Zhejiang Key Laboratory of Quantum State Control and Optical Field Manipulation Department of Physics Zhejiang Sci-Tech University 928 Second Avenue Xiasha Higher Education Zone Zhejiang province Hangzhou310018 China

Over the past century, the Boltzmann entropy has been widely accepted as the standard definition of entropy for an isolated system. However, it coexists with controversial alternatives, such as the Gibbs entropy. These definitions, including the Boltzmann entropy, exhibit certain inconsistencies, both mathematically and thermodynamically. To address this challenge, we introduce the estimation theory in statistical inference into the study of thermodynamics and statistical physics for finite-sized systems. By regarding the finite-sized system as a thermometer used to measure the temperature of the heat reservoir, we show that optimal estimation of temperature yields the corresponding entropy formula for an isolated system. In the single-sample case, optimal estimation of inverse temperature (or temperature) corresponds to the Boltzmann entropy (or Gibbs entropy). These different definitions of entropy, rather than being contradictory, apply to optimal estimation of different parameters. Furthermore, via the Laplace transform, we identify a complementarity between estimation of temperature and system's energy, a concept suggested by Niels Bohr. We also correct the energy-temperature uncertainty relation, as expressed by the Cramér-Rao bound, in the large-N limit. In the multiplesample case, we generalize the definitions of both Boltzmann entropy and Gibbs entropy to achieve optimal estimation of temperature, revealing the tight connection between statistical inference and Terrell Hill's nanothermodynamics. © 2025, CC BY.

关键词： Cramer-Rao bounds

Frustration Elimination and Excited state Search in Coherent Ising Machines

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Physical Review Letters 2025年第9期134卷 090401-090401页

作者： Zheng-Yang Zhou Clemens Gneiting J. Q. You Franco Nori Zhejiang Key Laboratory of Quantum State Control and Optical Field Manipulation Department of Physics Zhejiang Sci-Tech University 310018 Hangzhou China Theoretical Quantum Physics Laboratory Cluster for Pioneering Research RIKEN Wakoshi Saitama 351-0198 Japan Center for Quantum Computing RIKEN Wakoshi Saitama 351-0198 Japan Zhejiang Key Laboratory of Micro-Nano Quantum Chips and Quantum Control School of Physics and State Key Laboratory for Extreme Photonics and Instrumentation Zhejiang University Hangzhou 310027 China College of Optical Science and Engineering Zhejiang University Hangzhou 310027 China Physics Department The University of Michigan Ann Arbor Michigan 48109-1040 USA

Frustration, that is, the impossibility of satisfying the energetic preferences between all spin pairs simultaneously, underlies the complexity of many fundamental properties in spin systems, including the computational difficulty in determining their ground states. Coherent Ising machines (CIMs) have been proposed as a promising analog computational approach to efficiently find different degenerate ground states of large and complex Ising models. However, CIMs also face challenges in solving frustrated Ising models: frustration not only reduces the probability of finding good solutions, but it also prohibits the leveraging of quantum effects in doing so. To circumvent these detrimental effects of frustration, we show how frustrated Ising models can be mapped to frustration-free CIM configurations by including ancillary modes and modifying the coupling protocol used in current CIM designs. Such frustration elimination may empower current CIMs to benefit from quantum effects in dealing with frustrated Ising models. In addition, these ancillary modes can also enable error detection and searching for excited states.

关键词： Ising model

Deep Learning approaches for nuclear binding energy prediction: A comparative study of RNN, GRU and LSTM Models

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arXiv 2025年

作者： Jalili, Amir Pan, Feng Chen, Ai Xi Draayer, Jerry P. Zhejiang Key Laboratory of Quantum State Control and Optical Field Manipulation Department of Physics Zhejiang Sci-Tech University Hangzhou310018 China Department of Physics Liaoning Normal University Dalian116029 China Department of Physics and Astronomy Louisiana State University Baton RougeLA70803-4001 United States

This study investigates the application of deep learning models-recurrent neural networks, gated recurrent units, and long short-term memory networks-for predicting nuclear binding energies. Utilizing data from the Atomic Mass Evaluation (AME2020), we incorporate key nuclear structure features, including proton and neutron numbers, as well as additional terms from the liquid drop model and shell effects. Our comparative analysis demonstrates that the gated recurrent units model achieves the lowest root-mean-square error (σRMSE) of 0.326 MeV, surpassing traditional regression-based approaches. To assess model reliability, we validate predictions using the Garvey-Kelson relations, obtaining an error of 0.202 MeV, and further test extrapolation capabilities using the WS, WS3, and WS4 models. The extrapolation analysis confirms the robustness of our approach, particularly in predicting binding energies for nuclei near the driplines. These results highlight the effectiveness of deep learning in nuclear BE predictions, highlighting its potential to enhance the accuracy and reliability of theoretical nuclear models. © 2025, CC BY.

关键词： Extrapolation

High Responsivity, Ultra-Flexible, Self-Driven Solar-Blind Fibrous Photoelectrochemical Detector for Seawater Antibiotic Detection

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SSRN

SSRN 2025年

作者： Wu, Gang Chen, Kai Ni, Yizhou Wu, Chao Liu, Jinsong Hu, Haizheng Zhang, Xuehua Wang, Shunli Wu, Fengmin Wu, Zhengyuan Guo, Daoyou Zhejiang Key Laboratory of Quantum State Control and Optical Field Manipulation Department of Physics Zhejiang Sci-Tech University Hangzhou310018 China Incorporated Hangzhou310018 China Yiwu Huading Nylon Co. LTD Yiwu322000 China Institute of Optoelectronics Fudan University Shanghai200433 China

The detection of antibiotics in seawater is essential for ensuring the safety and sustainability of the marine environment. However, existing detection methods are hindered by limitations such as slow response times, complex operations, or high costs. In this study, we propose the omnidirectional growth of high-quality α-Ga2O3 nanopillar arrays on a flexible carbon nanotube fiber (CNTF) substrate to construct a self-powered fibrous photoelectrochemical sensor for antibiotic detection. Importantly, the device effectively mitigates signal interference from ambient light and seawater fluctuations due to its ultra-flexibility and solar-blind response characteristics. Specifically, a significant responsivity of 61.6 mA/W, a detectivity of 3.03 × 1011 Jones, and an external quantum efficiency of 30.1% are obtained and outperforming most fibrous photodetectors. Moreover, the device with 360° omnidirectional detection capability exhibited no significant degradation of photoresponse during 2000 bending cycles or long-term continuous operation. Notably, under both affections of enhancing the separation efficiency of photogenerated carriers by organic ions and competing for solar-blind UV light absorption between antibiotic molecules and Ga2O3, the α-Ga2O3@CNTF detector demonstrates the capability to detect sulfonamides, quinolones, and tetracyclines at various concentrations in seawater. This work provides valuable insights into developing high-performance, cost-effective, and user-friendly devices for advanced seawater antibiotic detection technology. © 2025, The Authors. All rights reserved.

关键词： Seawater

Floquet geometric squeezing in fast-rotating condensates

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arXiv 2025年

作者： Chen, Li Zhu, Fei Zhang, Yunbo Pu, Han Institute of Theoretical Physics State Key Laboratory of Quantum Optics and Quantum Optics Devices Shanxi University Taiyuan030006 China Key Laboratory of Optical Field Manipulation of Zhejiang Province and Physics Department of Zhejiang Sci-Tech University Hangzhou310018 China Department of Physics and Astronomy Smalley-Curl Institute Rice University HoustonTX77005 United States

Constructing and manipulating quantum states in fast-rotating Bose-Einstein condensates (BEC) has long stood as a significant challenge as the rotating speed approaching the critical velocity. Although the recent experiment [Science, 372, 1318 (2021)] has realized the geometrically squeezed state of the guiding-center mode, the remaining degree of freedom, the cyclotron mode, remains unsqueezed due to the large energy gap of Landau levels. To overcome this limitation, in this paper, we propose a Floquet-based state-preparation protocol by periodically driving an anisotropic potential. This protocol not only facilitates the single cyclotron-mode squeezing, but also enables a two-mode squeezing. Such two-mode squeezing offers a richer set of dynamics compared to single-mode squeezing and can achieve wavepacket width well below the lowest Landau level limit. Our work provides a highly controllable knob for realizing diverse geometrically squeezed states in ultracold quantum gases within the quantum Hall regime. Copyright © 2025, The Authors. All rights reserved.

关键词： Cyclotrons

Spin-density wave and superconductivity in La4Ni3O10 under ambient pressure

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Physical Review B 2025年第14期111卷 144502-144502页

作者： Ming Zhang Hongyi Sun Yu-Bo Liu Qihang Liu Wei-Qiang Chen Fan Yang Zhejiang Key Laboratory of Quantum State Control and Optical Field Manipulation Department of Physics Zhejiang Sci-Tech University Hangzhou 310018 China Shenzhen Institute for Quantum Science and Engineering Southern University of Science and Technology Shenzhen 518055 China International Quantum Academy Shenzhen 518048 China Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100190 China Department of Physics State key laboratory of quantum functional materials and Guangdong Basic Research Center of Excellence for Quantum Science Southern University of Science and Technology Shenzhen 518055 China Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area Shenzhen 518045 China School of Physics Beijing Institute of Technology Beijing 100081 China

High-pressure studies have revealed superconductivity in La4Ni3O10, sparking interest in its ambient-pressure properties and the underlying electronic correlations. Motivated by experimental observations of an incommensurate spin-density wave (SDW) at ambient pressure, we investigate the SDW characteristics and possible superconductivity in La4Ni3O10 using a multiorbital random-phase approximation (RPA). Starting with a 12-orbital tight-binding model derived from density functional theory (DFT) calculations, we include Hubbard interactions to explore the interplay between electronic correlations and magnetic instabilities. Our analysis reveals a stripe-like SDW with a wave vector Q≈(±0.7π,0), suggesting a possible density wave instability in agreement with experiments. This configuration is driven by nesting between the α1 pocket, primarily contributed by the outer-layer Ni dz2 orbitals, and the β1 pocket, contributed by both the dz2 and dx2−y2 orbitals of the outer layer. It exhibits interlayer antiferromagnetic ordering between the top and bottom NiO layers, with the magnetic moment of the middle layer being nearly zero. We demonstrate that the Hund coupling JH is the primary driver of the observed SDW and determine the specific criterion: JH>0.16U. Building upon our findings on the SDW mechanism, we further demonstrate that hole doping (δ=−0.4) enhances Fermi surface nesting, leading to the emergence of a superconducting state with a gap structure similar to that of the high-pressure phase.

关键词： Spin density waves

Homochiral carbon nanotube van der Waals crystals

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Science (New York, N.Y.) 2025年第6740期387卷 1310-1316页

作者： Zhang, Zhichun Chen, Yi Shen, Peiyue Chen, Jiajun Wang, Sen Wang, Bo Ma, Saiqun Lyu, Bosai Zhou, Xianliang Lou, Shuo Wu, Zhenghan Xie, Yufeng Zhang, Chengjia Wang, Liguo Xu, Kunqi Li, Haonan Wang, Guohua Watanabe, Kenji Taniguchi, Takashi Qian, Dong Jia, Jinfeng Liang, Qi Wang, Xiaoqun Yang, Wei Zhang, Guangyu Jin, Chuanhong Ouyang, Wengen Shi, Zhiwen Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education) Shanghai Jiao Tong University School of Physics and Astronomy and Tsung-Dao Lee Institute Shanghai China Department of Engineering Mechanics School of Civil Engineering Wuhan University Wuhan Hubei China State Key Laboratory of Water Resources Engineering and Management Wuhan University Wuhan Hubei China State Key Laboratory of Silicon and Advanced Semiconductor Materials School of Materials Science and Engineering Zhejiang University Hangzhou Zhejiang China Research Center for Electronic and Optical Materials National Institute for Materials Science Tsukuba Japan Research Center for Materials Nanoarchitectonics National Institute for Materials Science Tsukuba Japan Collaborative Innovation Centre of Advanced Microstructures Nanjing University Nanjing China School of Physics and Institute for Advanced Studies of Physics Zhejiang University Hangzhou Zhejiang China Beijing National Laboratory for Condensed Matter Physics Key Laboratory for Nanoscale Physics and Devices Institute of Physics Chinese Academy of Sciences Beijing China Songshan Lake Materials Laboratory Dongguan China State Key Laboratory of Micro-Nano Engineering Science Shanghai Jiao Tong University Shanghai China

For applications of single-walled carbon nanotubes (SWNTs) in integrated circuits, it is crucial to have high-tube density arrays of SWNTs that are well aligned and purely semiconducting. In this work, we report on the direct growth of close-packed SWNT arrays on hexagonal boron nitride (hBN) substrates, demonstrating high alignment and uniform chirality within each array. Molecular dynamics simulations suggest that a self-assembly growth mechanism resulted from the intertube van der Waals attraction and the ultralow sliding friction of SWNTs on the atomically flat hBN substrate. field-effect transistors constructed from the grown SWNT array exhibit high performance at room temperature, with mobilities of up to 2000 square centimeters per volt per second, on/off ratios of ~107, and a maximum current density of ~6 milliamperes per micrometer.

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Defect passivation in randomly oriented Ruddlesden-Popper perovskite LEDs via intrinsic solvent mediated Ostwald ripening process

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optical Materials 2025年

作者： Lingbo Xu Wenchuan Wang Liu Zhang Siyuan Che Can Cui Zhejiang Key Laboratory of Quantum State Control and Optical Field Manipulation Department of Physics Zhejiang Sci-Tech University Hangzhou 310018 People’s Republic of China

Ruddlesden-Popper (RP) phase perovskites with two dimensional (2D) nanoplatelets separated by bulky organic cations provide effective carrier confinement and are favorable for light-emitting diodes (LEDs). Since insulating organic cations arranged in a preferred in-plane orientation would impede carrier transport, randomly stacking configuration of perovskite nanocrystals has been applied in previous reports to facilitate carrier injection, yielding a boost of current efficiency. However, random orientation inevitably results in many defects at grain boundaries, limiting the overall performances of LEDs. In this report, thermal induced and intrinsic solvent-mediated Ostwald ripening process has been utilized to heal defects in randomly oriented RP perovskites. The Ostwald ripening process leads to a slight increase of grain size while maintaining the randomly stacking configuration of crystals. As a result, the optical properties of randomly oriented RP perovskites could be significantly improved without deteriorating the electrical properties. By optimizing the annealing temperature, the modified RP perovskites deliver a champion photoluminescence quantum yield of 56.7% and a champion current efficiency of 27.08 cd/A for corresponding LEDs, which are more than 4 times higher than those of the unmodified one. This work thus provides a facile strategy to produce high-performance perovskite LEDs.

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