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arXiv 2021年

作者： Li, Fei-Chen Tang, Yong-Bo Qiao, Hao-Xue Shi, Ting-Yun Department of Physics Wuhan University Wuhan430072 China College of Engineering Physics Shenzhen Technology University Shenzhen518118 China State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics Innovation Academy for Precision Measurement Science and Technology Chinese Academy of Sciences Wuhan430071 China

Hyperfine-structure constants of odd Ra+ due to the interactions of nuclear magnetic dipole, electric quadrupole, and magnetic octupole moments with the electrons are investigated in the framework of relativistic coupled-cluster method within single- and double-excitation approximation. The calculated energies and magnetic dipole hyperfine-structure constants A exhibit a good agreement with available experimental values. Combining with the experimental electric quadrupole hyperfine-structure constant, we also extracted the electric quadrupole moments Q of 209,211,221,223Ra. Our Q(221Ra) and Q(223Ra) are consistent with the referenced values from a semi-empirical analysis (Z. Phys. D: At., Mol. Clusters 11, 105 (1988)), but Q(211Ra)=0.33(2) is smaller than the referenced value 0.48(4) by about 30%. Furthermore, we also performed a procedure for assessing the contributions of magnetic octupole moment to the hyperfine splitting. The sensitivity of hyperfine-structure interval measurements in 223Ra+ that can reveal the effect caused by the nuclear octupole moment are found to be on the order of kHz. © 2021, CC BY.

关键词： Magnetism

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Versatile on-chip light coupling and(de)multiplexing from arbitrary polarizations to controlled waveguide modes using an integrated dielectric metasurface

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Photonics Research 2020年第4期8卷 564-576页

作者： YUAN MENG ZHOUTIAN LIU ZHENWEI XIE RIDE WANG TIANCHENG QI FUTAI HU HYUNSEOK KIM QIRONG XIAO XING FU QIANG WU SANG-HOON BAE MALI GONG XIAOCONG YUAN State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China Research Laboratory of Electronics Massachusetts Institute of TechnologyCambridgeMassachusetts 02139USA Key Laboratory of Photonic Control Technology Ministry of EducationTsinghua UniversityBeijing 100084China Nanophotonics Research Centre Shenzhen Key Laboratory of Micro-Scale Optical Information TechnologyShenzhen UniversityShenzhen 518060China Key Laboratory of Weak-Light Nonlinear Photonics Ministry of EducationTEDA Institute of Applied Physics and School of PhysicsNankai UniversityTianjin 300457China Department of Mechanical Engineering Massachusetts Institute of TechnologyCambridgeMassachusetts 02139USA

Metasurfaces have found broad applicability in free-space optics,while its potential to tailor guided waves remains barely *** synergizing the Jones matrix model with generalized Snell’s law under the phase-matching condition,we propose a universal design strategy for versatile on-chip mode-selective coupling with polarization sensitivity,multiple working wavelengths,and high efficiency *** coupling direction,operation frequency,and excited mode type can be designed at will for arbitrary incident polarizations,outperforming previous technology that only works for specific polarizations and lacks versatile mode ***,using silicon-nanoantenna-patterned silicon-nitride photonic waveguides,we numerically demonstrate a set of chip-scale optical couplers around 1.55μm,including mode-selective directional couplers with high coupling efficiency over 57%and directivity about 23 d *** and wavelength demultiplexer scenarios are also proposed with 67%maximum efficiency and an extinction ratio of 20 d ***,a chip-integrated twisted light generator,coupling free-space linear polarization into an optical vortex carrying 1 h orbital angular momentum(OAM),is also reported to validate the mode-control *** comprehensive method may motivate compact wavelength/polarization(de)multiplexers,multifunctional mode converters,on-chip OAM generators for photonic integrated circuits,and high-speed optical telecommunications.

关键词： Versatile on-chip light arbitrary polarizations waveguide modes an integrated dielectric metasurface

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Optical vortices 30 years on:OAM manipulation from topological charge to multiple singularities

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Light(Science & Applications) 2019年第1期8卷 339-367页

作者： Yijie Shen Xuejiao Wang Zhenwei Xie Changjun Min Xing Fu Qiang Liu Mali Gong Xiaocong Yuan Key Laboratory of Photonic Control Technology(Tsinghua University) Ministry of Education100084 BeijingChina State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua University100084 BeijingChina National Engineering Laboratory for Public Safety Risk Perception and Control by Big Data(NELPSRPC) China Academy of Electronics and Information Technology of CETCChina Electronic Technology Group Corporation100041 BeijingChina Nanophotonics Research Center Shenzhen University518060 ShenzhenChina

Thirty years ago,Coullet et *** that a special optical field exists in laser cavities bearing some analogy with the superfluid *** then,optical vortices have been widely studied,inspired by the hydrodynamics sharing similar *** to a fluid vortex with a central flow singularity,an optical vortex beam has a phase singularity with a certain topological charge,giving rise to a hollow intensity *** a beam with helical phase fronts and orbital angular momentum reveals a subtle connection between macroscopic physical optics and microscopic quantum *** amazing properties provide a new understanding of a wide range of optical and physical phenomena,including twisting photons,spin–orbital interactions,Bose-Einstein condensates,etc.,while the associated technologies for manipulating optical vortices have become increasingly tunable and ***,owing to these salient properties and optical manipulation technologies,tunable vortex beams have engendered tremendous advanced applications such as optical tweezers,high-order quantum entanglement,and nonlinear *** article reviews the recent progress in tunable vortex technologies along with their advanced applications.

关键词： tunable optics charge

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In-Plane Dual-Gated Spin-Valve Device Based on the Zigzag Graphene Nanoribbon

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Physical Review Applied 2020年第4期13卷 044006-044006页

作者： Min Zhou Hao Jin Yanxia Xing Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement Ministry of Education Micronano Centre Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems Beijing Institute of Technology Beijing 100081 China Shenzhen Key Laboratory of Advanced Thin Films and Applications College of Physics and Optoelectronic Engineering Shenzhen University Shenzhen 518060 China

Using the nonequilibrium Green’s function combined with density-functional theory, we systematically study the transport properties of the zigzag graphene nanoribbon (ZGNR). When an external transverse electric field is applied, a ZGNR can exhibit half-metallic characteristics with its conductive channel localized at the edge positions. Accordingly, an in-plane dual-gated spin-valve device is proposed. Thanks to its unique design, the proposed device overcomes the bottleneck of current leakage and avoids contact issues. Remarkably, a 100% spin injection efficiency and a giant tunnel magnetoresistance of up to 107 are realized, which represent much better performance than that of traditional magnetic tunnel junctions. In addition, we also explore the effect of architecture reconstruction and impurity doping on spin-polarized transport. It is found that, in general, the tunneling process is hindered if disorder occurs at the conductive edge. By contrast, if we put the deformation or impurities away from the conductive edge, the transport properties may be barely degraded or even improved, depending on the type of disorder. It should be possible to apply these ubiquitous underlying principles to other materials, which could inspire the design of alternative spintronic devices with high performance.

关键词： Edge states Quantum transport Spintronics Graphene Nanoribbon Spin valves Density functional calculations Nonequilibrium Green's function

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Intermediate anomalous Hall states induced by noncollinear spin structure in the magnetic topological insulator MnBi2Te4

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Physical Review B 2021年第5期104卷 054409-054409页

作者： Jing-Zhi Fang Shuo Wang Xing-Guo Ye Ben-Chuan Lin An-Qi Wang Hao-Nan Cui Jian-Kun Wang Guang-Yu Zhu Song Liu Yongkai Li Zhiwei Wang Yugui Yao Zhongming Wei Dapeng Yu Zhi-Min Liao Shenzhen Institute for Quantum Science and Engineering Southern University of Science and Technology Shenzhen 518055 China State Key Laboratory of Superlattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences & Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Beijing 100083 China State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics School of Physics Peking University Beijing 100871 China Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement Ministry of Education School of Physics Beijing Institute of Technology Beijing 100081 China Micronano Center Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems Beijing Institute of Technology Beijing 100081 China

The combination of topology and magnetism is attractive to produce exotic quantum matters, such as the quantum anomalous Hall state, axion insulators, and the magnetic Weyl semimetals. MnBi2Te4, as an intrinsic magnetic topological insulator, provides a platform for the realization of various topological phases. Here we report the intermediate Hall steps in the magnetic hysteresis of MnBi2Te4, where four distinguishable magnetic memory states at zero magnetic field are revealed. The gate and temperature dependence of the magnetic intermediate states indicates the noncollinear spin structure in MnBi2Te4, which can be attributed to the Dzyaloshinskii-Moriya interaction as the coexistence of strong spin-orbit coupling and local inversion symmetry breaking on the surface. Moreover, these multiple magnetic memory states can be programmatically switched among each other through applying designed pulses of magnetic field. Our results provide some insights of the influence of bulk topology on the magnetic states, and the multiple memory states should be promising for spintronic devices.

关键词： Anomalous Hall effect Magnetism Topological materials

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On-chip Reconfigurable Optical Neural Networks

Research Square

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Research Square 2021年

作者： Zhao, Xianmeng Lv, Haibin Chen, Cheng Tang, Shenjie Liu, Xiaoping Qi, Qin School of Physical Science and Technology ShanghaiTech University Shanghai201210 China Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai201800 China University of Chinese Academy of Sciences Beijing100049 China College of Physics and Optoelectronic Engineering Shenzhen University Shenzhen100049 China Shenzhen Key Laboratory of Intelligent Optical Measurement and Detection Shenzhen100049 China

Implementing artificial neural networks on integrated platforms has generated significant interest in recent years. Several architectures for on-chip optical networks with basic functionalities have been successfully demonstrated, for example, optical spiking neurosynaptic, photonic convolution accelerator, and nanophotonic/electronic hybrid deep neuron networks. In this work, we propose a layered coherent silicon-on-insulator diffractive optical neural network, of which the inter-layer phase delay can be actively tuned. By forming a close-loop with control electronics, we further demonstrate that our fabricated on-chip neural network can be trained in-situ and consequently reconfigured to perform various tasks, including full adder operation and vowel recognition, while achieving almost the same accuracy as networks trained on conventional computers. Our results show that the proposed optical neural network could potentially pave the way for future optical artificial intelligence hardware. © 2021, CC BY.

关键词： Silicon on insulator technology

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Synergistic wedge effect for low-temperature doping in dual-phase dielectric ceramics

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Journal of Materials Science & technology 2025年

作者： Yanzhao Zhang GuoXiang Zhou Yuhang Zhang Ning Xie Lanlan Yang Kunpeng Lin Zhe Zhao Meiling Yang Huatay Lin Zhihua Yang Dechang Jia Yu Zhou Institute for Advanced Ceramics School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China Chongqing Research Institute Harbin Institute of Technology Chongqing 401135 China Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials University of Jinan Jinan 250000 China School of Microelectronics and Communication Engineering Chongqing University Chongqing 400044 China School of Electromechanical Engineering Guangdong University of Technology Guangzhou 510006 China School of Materials Science and Engineering Harbin Institute of Technology (Shenzhen) Shenzhen 518055 China

Selective ion doping is a promising method to enhance the overall performance of perovskite dielectric ceramics. However, the confrontations among the dielectric constant ( ε r ), near-zero temperature coefficient of resonant frequency (TCF), and quality factor ( Q × f ) remain key challenges in high-performance dielectric ceramics. To leverage the trade-off conflicts, using dual-phase perovskite-based dielectric ceramic composites could be a potentially ideal solution. Unfortunately, the selected ions are hard to be doped into the perovskite phase due to the sintering temperature disparity of the two phases, thereby significantly impacting the modification effect. In this study, a “wedge” strategy was employed in a MgTiO 3 -CaTiO 3 dual-phase dielectric ceramic composite by using Ce as an auxiliary dopant to realize the main Hf doping in the CaTiO 3 phase due to the lattice distortion. This strategy also harmonizes the confrontation of the sintering temperature disparity between the two components of CaTiO 3 and MgTiO 3 . The Hf 4+ doping level of as high as 40 mol.% with a reduced sintering temperature of over 200 °C was successfully achieved by using this “wedge” strategy. Most importantly, the trade-off conflicts among the ε r , near-zero TCF, and Q × f have been considerably reduced and harmonized due to the successful introduction of a high dosage of Hf dopant in the CaTiO 3 phase without sacrificing the intact structure of MgTiO 3 . This strategy not only sheds light on manufacturing high-performance dual-phase dielectric ceramics with trade-off conflicts of properties but also provides an innovative pathway to address the challenge of mismatch of sintering temperature for selective ion doping in multiple-phase ceramic composites.

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Bhatia-Davis formula in the quantum speed limit

arXiv

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arXiv 2021年

作者： Liu, Jing Miao, Zibo Fu, Libin Wang, Xiaoguang MOE Key Laboratory of Fundamental Physical Quantities Measurement PGMF and School of Physics Huazhong University of Science and Technology Wuhan430074 China School of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen Shenzhen518055 China Graduate School China Academy of Engineering Physics Beijing100193 China Zhejiang Institute of Modern Physics Department of Physics Zhejiang University Hangzhou310027 China

The Bhatia-Davis theorem provides a useful upper bound for the variance in mathematics, and in quantum mechanics, the variance of a Hamiltonian is naturally connected to the quantum speed limit due to the Mandelstam-Tamm bound. Inspired by this connection, we construct a formula, referred to as the Bhatia-Davis formula, for the characterization of the quantum speed limit in the Bloch representation. We first prove that the Bhatia-Davis formula is an upper bound for a recently proposed operational definition of the quantum speed limit, which means it can be used to reveal the closeness between the timescale of certain chosen states to the systematic minimum timescale. In the case of the largest target angle, the Bhatia-Davis formula is proved to be a valid lower bound for the evolution time to reach the target when the energy structure is symmetric. Regarding few-level systems, it is also proved to be a valid lower bound for any state in two-level systems with any target, and for most mixed states with large target angles in equally spaced three-level systems. © 2021, CC BY-NC-SA.

关键词： Speed

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Discovery of smectic charge and pair-density-wave orders in topological monolayer 1T′-MoTe2

arXiv

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arXiv 2023年

作者： Wei, Li-Xuan Xiao, Peng-Cheng Li, Fangsen Wang, Li Deng, Bo-Yuan Cheng, Fang-Jun Zheng, Fa-Wei Hao, Ning Zhang, Ping Ma, Xu-Cun Xue, Qi-Kun Song, Can-Li State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics Tsinghua University Beijing100084 China School of Physics and Physical Engineering Qufu Normal University Qufu273165 China Vacuum Interconnected Nanotech Workstation Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of Sciences Suzhou215123 China Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement School of Physics Beijing Institute of Technology Beijing100081 China Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field Laboratory HFIPS Chinese Academy of Sciences Hefei230031 China Institute of Applied Physics and Computational Mathematics Beijing100088 China Frontier Science Center for Quantum Information Beijing100084 China Shenzhen Institute for Quantum Science and Engineering Department of Physics Southern University of Science and Technology Shenzhen518055 China Beijing Academy of Quantum Information Sciences Beijing100193 China

Symmetry-breaking phenomena are observed in numerous strongly-correlated systems including high-temperature superconductors. However, identifying these exotic phases and understanding their interplay with superconductivity in topological materials remain challenging. Here we employ a cryogenic scanning tunneling microscopy to discover a unidirectional (striped) charge order (CO) and a primary pair-density-wave (PDW) in topological monolayer 1T′-MoTe2. The two orders are spatially modulated uniaxially and share the same periodicity of five-unit cells or a wavevector QC ͌ QP ͌ (0, 0.4)π/b (b is the lattice constant along the Mo chains). Importantly, the primary PDW state features a two-gap superconductivity below the transition temperature of 6.0 K and induces another unique particle-hole-symmetric CO at twice the PDW wavevector. Combining these results and our density functional calculations, we reveal that the two striped orders are primarily driven by nesting behaviors between electron and hole pockets. Our findings establish monolayer 1T′-MoTe2 as a topological paradigm for exploring multiple preexisting symmetry-breaking states. © 2023, CC BY.

关键词： Monolayers

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Fully Automated Deep Learning Enabled Miniature Mass Spectrometry System for Psychoactive Therapeutic Drug Monitoring

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Advanced science (Weinheim, Baden-Wurttemberg, Germany) 2025年 e02721页

作者： Yuanhao Zhou Jiawen Ai Zi Ye Kexin Chen JingXiong Lin Zhenhua Zhang Mi Luo Benjie Zhou Shijian Xiang Jianhua Zhou Xinming Huo School of Biomedical Engineering Shenzhen Campus of Sun Yat-sen University Shenzhen 518107 China. Key Laboratory of Sensing Technology and Biomedical Instruments of Guangdong Province School of Biomedical Engineering Sun Yat-sen University Guangzhou 510275 China. Division of Advanced Manufacturing Graduate School at Shenzhen Tsinghua University Shenzhen 518055 China. State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision Instrument Tsinghua University Beijing 100084 China. School of Pharmaceutical Sciences (Shenzhen) Shenzhen Campus of Sun Yat-sen University Shenzhen 518107 China. Shenzhen Key Laboratory of Chinese Medicine Active Substance Screening and Translational Research Department of Pharmacy The Seventh Affiliated Hospital Sun Yat-sen University Shenzhen 518107 China. CHIN Instrument (Hefei) Co. Ltd. Hefei 231200 China.

Advancing precision medicine requires efficient small molecule biomarker detection in biofluids, yet existing methods encounter challenges in complexity, portability, and throughput. This study presents an integrated miniature blood processing and mass spectrometry (MS) analysis system, which incorporates automated magnetic solid-phase extraction, self-aspiration sampling miniature mass spectrometer, and deep learning algorithms for automated quantitative analysis. It achieves full automation from sample preparation to detection, demonstrating the capability to analyze serum psychoactive drugs with a 15-second/MS acquisition and 8-sample parallel processing within 30 minutes (including pretreatment). This has significantly increased detection throughput and facilitated the establishment of the standard curve. The novel dual-target ion parallel tandem MS analysis technique, combined with a U-net peak area recognition algorithm, achieved over 98% identification accuracy with less than 0.2% area prediction deviation. Quantitative analysis showed high correlation coefficients >0.99 in medically relevant ranges, supported by relative standard deviation < 10% and average back-calculated accuracy deviation < 3.5%. Clinical validation revealed strong concordance with LC-MS/MS. The system's integration of automated sample processing, miniature MS hardware, and AI-driven data analysis establishes a paradigm for high-throughput clinical detection. The advantages of accuracy, automation, intelligence, miniaturization, and high throughput suggest significant potential for this system in clinical detection and personalized medicine.

关键词： automated analysis clinical mass spectrometry intelligent diagnosis miniature mass spectrometer therapeutic drug monitoring

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