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Time-domain Landau-Zener-Stückelberg-Majorana interference in an optical lattice clock

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Physical Review A 2021年第5期104卷 053318-053318页

作者： Wei-Xin Liu (刘伟新) Tao Wang (汪涛) Xue-Feng Zhang (张学锋) Wei-Dong Li (李卫东) Institute of Theoretical Physics and Department of Physics State Key Laboratory of Quantum Optics and Quantum Optics Devices Collaborative Innovation Center of Extreme Optics Shanxi University Taiyuan 030006 China Department of Physics and Center of Quantum Materials and Devices Chongqing University Chongqing 401331 China Chongqing Key Laboratory for Strongly Coupled Physics Chongqing 401331 China Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material Technology Center for Advanced Material Diagnostic Technology and College of Engineering Physics Shenzhen Technology University Shenzhen 518118 China

The interference between a sequence of Landau-Zener (LZ) transitions can produce Rabi oscillations (LZROs). This phenomenon is a kind of time-domain Landau-Zener-Stückelberg-Majorana (LZSM) interference. However, experimental demonstrations of this LZSM interference induced Rabi oscillation are extremely hard due to the short coherence time of the driven quantum system. Here, we study theoretically the time-domain LZSM interference between the clock transition in a one-dimensional Sr87 optical lattice clock (OLC) system. With the help of both the adiabatic-impulse model and Floquet numerical simulation method, the LZROs with special steplike structure are clearly found both in the fast- and slow-passage limit in the real experiment parameter regions. In addition, the dephasing effect caused by the system temperature can be suppressed with destructive interference in the slow-passage limit. Finally, we discuss the possible Bloch-Siegert shift while the pulse time is away from the half-integer and integer periods. Our work provides a clear road map to observe the LZROs on the OLC platform.

关键词： Atomic & molecular processes in external fields Atomic spectra

On the existence of a proton halo in 22Al

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arXiv 2024年

作者： Zhang, K.Y. Pan, C. Wang, Sibo Institute of Nuclear Physics and Chemistry China Academy of Engineering Physics Sichuan Mianyang621900 China Department of Physics Anhui Normal University Anhui Wuhu241000 China Department of Physics Chongqing Key Laboratory for Strongly Coupled Physics Chongqing University Chongqing401331 China

More and more halo nuclei or candidates have been identified or suggested in experiments in recent years. It was declared that the halo structure of 22Al is revealed by the large isospin asymmetry in 22Si/22O mirror Gamow-Teller transitions [Phys. Rev. Lett. 125, 192503 (2020)]. We highlight that a significant mirror asymmetry already exists between wave functions of the likely unbound nucleus 22Si and the doubly-magic nucleus 22O, which largely explains the observed asymmetry in the transitions. Furthermore, these transitions involve only the 1+ excited states of the daughter nuclei 22Al and 22F. The 1+ state of 22Al cannot be considered a halo state due to its proton-unbound nature. An analysis of the spin-parity suggests that a weakly bound 2s1/2 valence proton in the ground-state 22Al is improbable. To investigate the shell structure for the ground state of 22Al, we employ the state-of-the-art deformed and triaxial relativistic Hartree-Bogoliubov theories in continuum. We find that a small s-wave component of 5% appears for the weakly bound valence proton in 22Al only when triaxial deformation is considered. While the examination of densities and rms radii indicates that this small s-wave component is insufficient to form a discernible proton halo in 22Al, slightly larger 2s1/2 occupations have been reported in other recent theoretical results. The question of how many low- components are sufficient to form a proton halo in the presence of the Coulomb barrier remains open. Thus, future measurements of reaction or interaction cross sections and momentum distributions of breakup fragments are highly desirable to verify whether 22Al is a halo nucleus. © 2024, CC BY.

关键词： Ground state

structure of the impurity band in heavily doped nonmagnetic semiconductors

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Physical Review B 2023年第13期107卷 134204-134204页

作者： Hongwei Chen Zi-Xiang Hu Department of Physics Northeastern University Boston Massachusetts 02115 USA Stanford Institute for Materials and Energy Sciences Stanford University Stanford California 94305 USA Linac Coherent Light Source SLAC National Accelerator Laboratory Menlo Park California 94720 USA Department of Physics and Chongqing Key Laboratory for Strongly Coupled Physics Chongqing University Chongqing 401331 People's Republic of China

We study the properties of the impurity band in heavily doped nonmagnetic semiconductors using the Jacobi-Davidson algorithm and the supervised deep learning method. The disorder averaged inverse participation ratio and Thouless number calculation show us the rich structure inside the impurity band. A convolutional neural network model, which is trained to distinguish the extended/localized phase of the Anderson model with high accuracy, shows us the results in good agreement with the conventional approach. Together, we find that there are three mobility edges in the impurity band for a specific on-site impurity potential, which means the presence of the extended states while filling the impurity band.

关键词： Density of states Convolutional neural networks Disordered systems Tight-binding model

Temperature-Dependent and Magnetism-Controlled Fermi Surface Changes in Magnetic Weyl Semimetals

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arXiv 2023年

作者： Zhang, Nan Ding, Xianyong Zhan, Fangyang Li, Houpu Li, Hongyu Tang, Kaixin Qian, Yingcai Pan, Senyang Xiao, Xiaoliang Zhang, Jinglei Wang, Rui Xiang, Ziji Chen, Xianhui CAS key Laboratory of Strongly-coupled Quantum Matter Physics Department of Physics University of Science and Technology of China Anhui Hefei230026 China Institute for Structure and Function Department of Physics Center for Quantum Materials and Devices Chongqing University Chongqing400044 China High Magnetic Field Laboratory Chinese Academy of Sciences Anhui Hefei230031 China Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing210093 China

The coupling between band structure and magnetism can lead to intricate Fermi surface modifications. Here we report on the comprehensive study of the Shubnikov-de Haas (SdH) effect in two rare-earth-based magnetic Weyl semimetals, NdAlSi and CeAlSi0.8Ge0.2. The results show that the temperature evolution of topologically nontrivial Fermi surfaces strongly depends on magnetic configurations. In NdAlSi, the SdH frequencies vary with temperature in both the paramagnetic state and the magnetically ordered state with a chiral spin texture, but become temperature independent in the high-field fully polarized state. In CeAlSi0.8Ge0.2, SdH frequencies are temperature-dependent only in the ferromagnetic state with magnetic fields applied along the c axis. First-principles calculations suggest that the notable temperature and magnetic-configuration dependence of Fermi surface morphology can be attributed to strong exchange coupling between the conduction electrons and local magnetic moments. Copyright © 2023, The Authors. All rights reserved.

关键词： Rare earths

Design monolayer iodinenes based on halogen bond and tiling theory

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arXiv 2023年

作者： Yu, Kejun Fu, Botao Zhang, Runwu Ma, Da-Shuai Li, Xiao-Ping Yu, Zhi-Ming Liu, Cheng-Cheng Yao, Yugui Liu, Yichen School of Physics Beijing Institute of Technology Beijing100081 China Beijing Key Lab of Nanophotonics & Ultrafine Optoelectronic Systems School of Physics Beijing Institute of Technology Beijing100081 China College of Physics and Electronic Engineering Center for Computational Sciences Sichuan Normal University Chengdu610068 China Institute for Structure and Function Department of Physics Chongqing Key Laboratory for Strongly Coupled Physics Chongqing University Chongqing400044 China Center of Quantum materials and devices Chongqing University Chongqing400044 China School of Physical Science and Technology Inner Mongolia University Hohhot010021 China

Xenes, two-dimensional (2D) monolayers composed of a single element, with graphene as a typical representative, have attracted widespread attention. Most of the previous Xenes, X from group-IIIA to group-VIA elements have bonding characteristics of covalent bonds. In this work, we for the first time unveil the pivotal role of a halogen bond, which is a distinctive type of bonding with interaction strength between that of a covalent bond and a van der Waals interaction, in 2D group-VIIA monolayers. Combing the ingenious non-edge-to-edge tiling theory and state-of-the-art ab initio method with refined local density functional M06-L, we provide a precise and effective bottom-up construction of 2D iodine monolayer sheets, iodinenes, primarily governed by halogen bonds, and successfully design a category of stable iodinenes, encompassing herringbone, Pythagorean, gyrated truncated hexagonal, i.e. diatomic-kagome, and gyrated hexagonal tiling pattern. These iodinene structures exhibit a wealth of properties, such as nontrivial novel topology, flat bands and fascinating optical characteristics, offering valuable insights and guidance for future experimental investigations. Our work not only unveils the unexplored halogen bonding mechanism in 2D materials but also opens a new avenue for designing other non-covalent bonding 2D materials. © 2023, CC BY.

关键词： Monolayers

A High-Capacity Ammonium Vanadate Cathode for Zinc-Ion Battery

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Nano-Micro Letters 2020年第5期12卷 153-164页

作者： Qifei Li Xianhong Rui Dong Chen Yuezhan Feng Ni Xiao Liyong Gan Qi Zhang Yan Yu Shaoming Huang Guangzhou Key Laboratory of Low-Dimensional Materials and Energy Storage Devices School of Materials and EnergyGuangdong University of TechnologyGuangzhou 510006People’s Republic of China Hefei National Laboratory for Physical Sciences at the Microscale Department of Materials Science and EngineeringCAS Key Laboratory of Materials for Energy ConversionUniversity of Science and Technology of ChinaHefei 230026People’s Republic of China Key Laboratory of Materials Processing and Mold(Zhengzhou University) Ministry of EducationZhengzhou UniversityZhengzhou 450002People’s Republic of China Aviation Fuel Research and Development Center China National Aviation Fuel Group LimitedBeijing 102603People’s Republic of China Department Institute for Structure and Function and of Physics Chongqing UniversityChongqing 400030People’s Republic of China Dalian National Laboratory for Clean Energy(DNL) Chinese Academy of SciencesDalian 116023LiaoningPeople’s Republic of China State Key Laboratory of Fire Science University of Science and Technology of ChinaHefei 230026People’s Republic of China

Given the advantages of being abundant in resources,environmental benign and highly safe,rechargeable zinc-ion batteries(ZIBs)enter the global spotlight for their potential utilization in large-scale energy *** their preliminary success,zinc-ion storage that is able to deliver capacity>400 mAh g^-1 remains a great ***,we demonstrate the viability of NH4V4O10(NVO)as high-capacity cathode that breaks through the bottleneck of ZIBs in limited *** first-principles calculations reveal that layered NVO is a good host to provide fast Zn^2+ions diffusion channel along its[010]direction in the interlayer *** the other hand,to further enhance Zn^2+ion intercalation kinetics and long-term cycling stability,a three-dimensional(3D)flower-like architecture that is self-assembled by NVO nanobelts(3D-NVO)is rationally designed and fabricated through a microwave-assisted hydrothermal *** a result,such 3D-NVO cathode possesses high capacity(485 mAh g^-1)and superior long-term cycling performance(3000 times)at 10 A g^-1(~50 s to full discharge/charge).Additionally,based on the excellent 3D-NVO cathode,a quasi-solid-state ZIB with capacity of 378 mAh g^-1is developed.

关键词： Zinc-ion battery Ammonium vanadate NH4V4O10

Precise determination of the top-quark on-shell mass Mt via its scale-invariant perturbative relation to the top-quark MS mass mt(mt)

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arXiv 2022年

作者： Huang, Xu-Dong Wu, Xing-Gang Zheng, Xu-Chang Yan, Jiang Wu, Zhi-Fei Ma, Hong-Hao Institute of High Energy Physics Chinese Academy of Sciences 19B Yuquan Road Shijingshan District Beijing100049 China Department of Physics Chongqing Key Laboratory for Strongly Coupled Physics Chongqing University Chongqing401331 China Department of Physics Guangxi Normal University Guilin541004 China

It has been shown that the principle of maximum conformality (PMC) provides a systematic way to solve conventional renormalization scheme and scale ambiguities. The scale-fixed predictions for physical observables using the PMC are independent of the choice of renormalization scheme - a key requirement of renormalization group invariance. In the paper, we derive new degeneracy relations based on the renormalization group equations that involve both the usual β-function and the quark mass anomalous dimension γm-function, respectively. These new degeneracy relations lead to an improved PMC scale-setting procedures, such that the correct magnitudes of the strong coupling constant and the MS-running quark mass can be fixed simultaneously. By using the improved PMC scale-setting procedures, the renormalization scale dependence of the MS-on-shell quark mass relation can be eliminated systematically. Consequently, the top-quark on-shell (or MS) mass can be determined without conventional renormalization scale ambiguity. Taking the top-quark MS mass mt(mt) = 162.5+2.1 -1.5 GeV as the input, we obtain Mt 172.41+2.21 -1.57 GeV. Here the uncertainties are combined errors with those also from Δαs(MZ) and the approximate uncertainty stemming from the uncalculated five-loop terms predicted through the Padé approximation approach. Copyright © 2022, The Authors. All rights reserved.

关键词： Germanium compounds

Topological Rashba-like edge states in large-gap quantum spin Hall insulators

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Physical Review Materials 2018年第11期2卷 114207-114207页

作者： Yuanjun Jin Li-Yong Gan Rui Wang Jinzhu Zhao Yueyue Shan Junfeng Liu Hu Xu Department of Physics and Institute for Quantum Science and Engineering Southern University of Science and Technology Shenzhen 518055 China School of Materials Science and Engineering Key Laboratory of Advanced Energy Storage Materials of Guangdong Province South China University of Technology 510641 Guangzhou China Institute for Structure and Function and Department of Physics Chongqing University 400030 Chongqing China

The search for large-band-gap quantum spin Hall (QSH) insulators, in which the dissipationless gapless edge states lie inside the bulk gap, is critical for their practical applications at room temperature. Based on first-principles calculations, we propose a sort of QSH insulator in a rectangular structure, i.e., AuSb, AuAs, and CuAs monolayers, which exhibits sizable bulk gaps up to 258 meV. These compounds host unexpected topological Rashba-like edge states, which exhibit strong dispersion with a nearly-free-electron feature. Such nontrivial edge states originate from spin-orbital coupling and an abrupt discontinuous potential across the surface. Furthermore, we argue that the AuSb monolayer can be epitaxially grown on a rutile TiO2(110) surface. Importantly, the thermodynamic stability of AuSb is enhanced while the topological features are perfectly preserved due to the weak van der Waals interaction at the interface. Our findings provide promising large-gap QSH candidates with exotic topological Rashba-like edge states that are in favor of experimental realization at room temperature.

关键词： Electronic structure First-principles calculations Rashba coupling Surface states Topological insulators

The effective potential of composite operator in the first order region of QCD phase transition

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arXiv 2023年

作者： Zheng, Hui-Wen Lu, Yi Gao, Fei Qin, Si-Xue Liu, Yu-Xin Department of Physics State Key Laboratory of Nuclear Physics and Technology Peking University Beijing100871 China School of Physics Beijing Institute of Technology Beijing100081 China Department of Physics Chongqing Key Laboratory for Strongly Coupled Physics Chongqing University Chongqing401331 China Collaborative Innovation Center of Quantum Matter Beijing100871 China Center for High Energy Physics Peking University Beijing100871 China

We propose a method to determine the effective potential of QCD from the gap equation, by introducing the homotopy method between the solutions of the equation of motion. Via this method, the effective potential beyond the bare vertex approximation is obtained, which then generalizes the Cornwall, Jackiw and Tomboulis (CJT) effective potential for the bilocal composite operators. Moreover, the extended effective potential is set to be a function of self energy instead of the propagator, which is the key point for the potential to be bounded from below. We then investigate the extended effective potential in the cases of phase transition of the QCD vacuum with a small current quark mass, and the first-order phase transition of QCD at finite temperature and high baryon chemical potential. In the former case, the effective potential shows as an inflection point at the critical mass where the multiple solutions of the Dyson-Schwinger equation (DSE) vanishes, which is consistent with that obtained by solving the DSE directly. For the latter case, the in-medium properties, such as the latent heat and the difference of trace anomaly, of QCD is obtained. Copyright © 2023, The Authors. All rights reserved.

关键词： Equations of motion