检索结果-内蒙古大学图书馆

arXiv 2018年

作者： Du, Z.Z. Wang, C.M. Li, Shuai Lu, Hai-Zhou Xie, X.C. Shenzhen Institute for Quantum Science and Engineering Department of Physics Southern University of Science and Technology Shenzhen518055 China Shenzhen Key Laboratory of Quantum Science and Engineering Shenzhen518055 China Peng Cheng Laboratory Shenzhen518055 China School of Physics Southeast University Nanjing211189 China Department of Physics Shanghai Normal University Shanghai200234 China International Center for Quantum Materials School of Physics Peking University Beijing100871 China Beijing Academy of Quantum Information Sciences Beijing100193 China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing100190 China

The nonlinear Hall effect has opened the door towards deeper understanding of topological states of matter. It can be observed as the double-frequency Hall voltage response to an ac longitudinal current in the presence of time-reversal symmetry. Disorder plays indispensable roles in various linear Hall effects, such as the localization in the quantized Hall effects and the extrinsic mechanisms of the anomalous, spin, and valley Hall effects. Unlike in the linear Hall effects, disorder enters the nonlinear Hall effect even in the leading order. However, the disorder-induced contribution to the nonlinear Hall effect has not been addressed. Here, we derive the formulas of the nonlinear Hall conductivity in the presence of disorder scattering. We apply the formulas to calculate the nonlinear Hall response of the tilted 2D Dirac model, which is the symmetry-allowed minimal model for the nonlinear Hall effect and can serve as a building block in realistic band structures. More importantly, we construct the general scaling law of the nonlinear Hall effect, which may help in experiments to distinguish disorder-induced contributions to the nonlinear Hall effect. This work will be instructive for exploring unconventional responses upon breaking discrete or crystal symmetries in emergent physical systems and materials. Copyright © 2018, The Authors. All rights reserved.

关键词： Crystal symmetry

来源：评论

学校读者我要写书评

暂无评论

Corrigendum: The Rb+–Rb collision rate in the energy range of 103–104 K (2020 J. Phys. B: At. Mol. Opt. Phys.53 135201)

引用

Journal of physics B: Atomic, Molecular and Optical physics 2020年第21期53卷

作者： Xiao-Kang Li Dian-Cheng Zhang Shuang-Fei Lv Jin-Yun Liu Feng-Dong Jia Yong Wu Xiao-He Lin Rui Li Xiang-Yuan Xu Ping Xue Xiao-Jing Liu Zhi-Ping Zhong School of Physical Sciences University of Chinese Academy of Sciences PO Box 4588 Beijing 100049 People's Republic of China Institute of Applied Physics and Computational Mathematics Beijing 100088 People's Republic of China Department of Physics Capital Normal University Beijing 100037 People's Republic of China State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics Tsinghua University and Collaborative Innovation Center of Quantum Matter Beijing 100084 People's Republic of China School Physical Science and Technology ShanghaiTech University Shanghai 201210 People's Republic of China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing 100190 People's Republic of China

来源：评论

学校读者我要写书评

暂无评论

Physical origins of ruled surfaces on the reduced density matrices geometry

引用

science China(physics,Mechanics & Astronomy) 2017年第2期60卷 1-8页

作者： Ji-Yao Chen Zhengfeng Ji Zheng-Xin Liu Xiaofei Qi Nengkun Yu Bei Zeng Duanlu Zhou State Key Laboratory of Low Dimensional Quantum Physics Department of Physics Tsinghua University Beijing 100084 China Perimeter Institute for Theoretical Physics Waterloo N2L 2Y5 Canada Centre for Quantum Computation ＆ Intelligent Systems School of Software Faculty of Engineering and Information Technology University of Technology Sydney Sydney 2007 Australia State Key Laboratory of Computer Science Institute of Software Chinese Academy of Sciences Beijing 100190 China Department of Physics Renmin University of China Beijing 100872 China Department of Mathematics Shanxi University Taiyuan 030000 China Institute for Quantum Computing University of Waterloo Waterloo N2L 3G1 Canada Department of Mathematics ＆ Statistics University of Guelph Guelph N1G 2W1 Canada Institute of Physics Chinese Academy of Sciences Beijing 100190 China

The reduced density matrices （RDMs） of many-body quantum states form a convex set. The boundary of low dimensional projections of this convex set may exhibit nontrivial geometry such as ruled surfaces. In this paper, we study the physical origins of these ruled surfaces for bosonic systems. The emergence of ruled surfaces was recently proposed as signatures of symmetry- breaking phase. We show that, apart from being signatures of symmetry-brealdng, ruled surfaces can also be the consequence of gapless quantum systems by demonstrating an explicit example in terms of a two-mode Ising model. Our analysis was largely simplified by the quantum de Finetti＇s theorem--in the limit of large system size, these RDMs are the convex set of all the symmetric separable states. To distinguish ruled surfaces originated from gapless systems from those caused by symmetry- breaking, we propose to use the finite size scaling method for the corresponding geometry. This method is then applied to the two-mode XY model, successfully identifying a ruled surface as the consequence of gapless systems.

关键词： ruled surfaces reduced density matrices bosonic system geometry

来源：评论

学校读者我要写书评

暂无评论

Origin of localization in Ti-doped Si

引用

Physical Review B 2018年第17期98卷 174204-174204页

作者： Yi Zhang R. Nelson K.-M. Tam W. Ku U. Yu N. S. Vidhyadhiraja H. Terletska J. Moreno M. Jarrell T. Berlijn Department of Physics & Astronomy Louisiana State University Baton Rouge Louisiana 70803 USA Center for Computation & Technology Louisiana State University Baton Rouge Louisiana 70803 USA Institute of Inorganic Chemistry RWTH Aachen University Landoltweg 1 52056 Aachen Germany Department of Physics and Astronomy Shanghai Jiao Tong University Shanghai 200240 China Department of Physics and Photon Science GIST Gwangju 61005 South Korea Theoretical Sciences Unit Jawaharlal Nehru Centre for Advanced Scientific Research Bangalore-560064 India Department of Physics and Astronomy Middle Tennessee State University Murfreesboro Tennessee 37132 USA Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge Tennessee 37831 USA Computer Science and Mathematics Division Oak Ridge National Laboratory Oak Ridge Tennessee 37831 USA

Intermediate band semiconductors hold the promise to significantly improve the efficiency of solar cells but only if the intermediate impurity band is metallic. We apply a recently developed first principles method to investigate the origin of electron localization in Ti doped Si, a promising candidate for intermediate band solar cells. We compute the critical Ti concentration and compare it against the available experimental data. Although Anderson localization is often overlooked in the context of intermediate band solar cells, our results show that in Ti doped Si it plays a more important role in the metal insulator transition than Mott localization. To this end we have devised a way to gauge the relative strengths of these two localization mechanisms that can be applied to study localization in doped semiconductors in general. Our findings have important implications for the theory of intermediate band solar cells.

关键词： Anderson localization Localization Disordered systems Solar cells First-principles calculations

来源：评论

学校读者我要写书评

暂无评论

Manipulation and Characterization of the Valley-Polarized Topological Kink States in Graphene-Based Interferometers

引用

Physical Review Letters 2018年第15期121卷 156801-156801页

作者： Shu-guang Cheng Haiwen Liu Hua Jiang Qing-Feng Sun X. C. Xie Department of Physics Northwest University Xi’an 710069 China Shaanxi Key Laboratory for Theoretical Physics Frontiers Xi’an 710069 China Center for Advanced Quantum Studies Department of Physics Beijing Normal University Beijing 100875 China School of Physical Science and Technology Soochow University Suzhou 215006 China Institute for Advanced Study Soochow University Suzhou 215006 China International Center for Quantum Materials School of Physics Peking University Beijing 100871 China Collaborative Innovation Center of Quantum Matter Beijing 100871 China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing 100190 China

Valley polarized topological kink states, existing broadly in the domain wall of hexagonal lattice systems, are identified in experiments. Unfortunately, only very limited physical properties are given. Using an Aharanov-Bohm interferometer composed of domain walls in graphene systems, we study the periodical modulation of a pure valley current in a large range by tuning the magnetic field or the Fermi level. For a monolayer graphene device, there exists one topological kink state, and the oscillation of the transmission coefficients has a single period. The π Berry phase and the linear dispersion relation of kink states can be extracted from the transmission data. For a bilayer graphene device, there are two topological kink states with two oscillation periods. Our proposal provides an experimentally feasible route to manipulate and characterize the valley-polarized topological kink states in classical wave and electronic graphene-type crystalline systems.

关键词： Quantum transport Topological effects in photonic systems Topological phases of matter Valleytronics Graphene Topological materials Landauer formula S-matrix method in transport

来源：评论

学校读者我要写书评

暂无评论

Thermodynamic resources in continuous-variable quantum systems

arXiv

引用

arXiv 2019年

作者： Narasimhachar, Varun Assad, Syed Binder, Felix C. Thompson, Jayne Yadin, Benjamin Gu, Mile School of Physical and Mathematical Sciences Nanyang Technological University Singapore637371 Singapore Complexity Institute Nanyang Technological University Singapore637335 Singapore Department of Quantum Science Centre for Quantum Computation and Communication Technology Australian National University CanberraACT2600 Australia Institute for Quantum Optics and Quantum Information-IQOQI Vienna Austrian Academy of Sciences Boltzmanngasse 3 Vienna1090 Austria Centre for Quantum Technologies National University of Singapore 3 Science Drive 2 Singapore117543 Singapore School of Mathematical Sciences University of Nottingham NottinghamNG7 2NR United Kingdom Atomic and Laser Physics Clarendon Laboratory University of Oxford Parks Road OxfordOX1 3PU United Kingdom

Thermodynamic resources, beyond their well-known usefulness in work extraction and other thermodynamic tasks, are often important also in tasks that are not evidently thermodynamic. Here we develop a framework for identifying such resources in diverse applications of bosonic continuous-variable systems. Introducing the class of bosonic linear thermal operations to model operationally-feasible processes, we apply this model to identify uniquely quantum properties of bosonic states that refine classical notions of thermodynamic resourcefulness. Among these are (1) a suite of temperature-like quantities generalizing the equilibrium temperature to quantum, non-equilibrium scenarios;(2) signal-to-noise ratios quantifying a system's capacity to carry information in phasespace displacement;and (3) well-established non-classicality measures quantifying the resolution in sensing and parameter estimation tasks. Copyright © 2019, The Authors. All rights reserved.

关键词： Thermodynamics

来源：评论

学校读者我要写书评

暂无评论

Surface superconductivity in the type II weyl semimetal TaIrTe4

arXiv

引用

arXiv 2018年

作者： Xing, Ying Shao, Zhibin Ge, Jun Wang, Jinhua Zhu, Zengwei Liu, Jun Wang, Yong Zhao, Zhiying Yan, Jiaqiang Mandrus, David Yan, Binghai Liu, Xiong-Jun Pan, Minghu Wang, Jian International Center for Quantum Materials School of Physics Peking University Beijing100871 China Beijing Key Laboratory of Optical Detection Technology for Oil and Gas Department of Materials Science and Engineering China University of Petroleum Beijing102249 China School of Physics Huazhong University of Science and Technology Wuhan430074 China Wuhan National High Magnetic Field Center Huazhong University of Science and Technology Wuhan430074 China Center of Electron Microscopy State Key Laboratory of Silicon Materials School of Materials Science and Engineering Zhejiang University Hangzhou310027 China Department of Materials Science and Engineering University of Tennessee KnoxvilleTN37996 United States Materials Science and Technology Division Oak Ridge National Laboratory Oak RidgeTN37831 United States Department of Condensed Matter Physics Weizmann Institute of Science Rehovot7610001 Israel CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing100190 China Department of Physics and Astronomy University of Tennessee KnoxvilleTN37996 United States Collaborative Innovation Center of Quantum Matter Beijing100871 China

The search for unconventional superconductivity in Weyl semimetal materials is currently an exciting pursuit, since such superconducting phases could potentially be topologically nontrivial and host exotic Majorana modes. The layered material TaIrTe4 is a newly predicted time-reversal invariant type II Weyl semimetal with minimum Weyl points. Here, by a systematical study based on electrical transport measurements at ultralow temperature and in ultrahigh magnetic field, we discover that TaIrTe4 crystals exhibit quasi-one-dimensional (quasi-1D) superconductivity with an onset transition temperature (Tc) up to 1.54 K, and show strong Shubnikov de Haas quantum oscillations. The normalized upper critical field h*(T/Tc) behavior indicates that the discovered superconductivity is unconventional with the p-wave pairing. The superconductivity is observed to be uniform on the sample surface with a V-shaped superconducting gap by scanning tunneling spectroscopy (STS). The STS further visualizes Fermi arc surface states that are consistent with the previous angle-resolved photoemission spectroscopy results. Both the transport and STS measurements reveal that the superconductivity occurs in the surface states and exhibits the quasi-1D features. Our results suggest that TaIrTe4 is a promising platform to explore topological superconductivity. Copyright © 2018, The Authors. All rights reserved.

关键词： Topology

来源：评论

学校读者我要写书评

暂无评论

Manipulation of magnetizations by spin-orbit torques

arXiv

引用

arXiv 2018年

作者： Li, Yucai Edmonds, Kevin William Liu, Xionghua Zheng, Houzhi Wang, Kaiyou State Key Laboratory of Superlattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences Beijing100083 China College of Materials Science and Opto-Electronic Technology University of Chinese Academy of Science Beijing100049 China School of Physics and Astronomy University of Nottingham NottinghamNG7 2RD United Kingdom CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Science Beijing100049 China

The control of magnetization by electric current is a rapidly developing area motivated by a strong synergy between breakthrough basic research discoveries and industrial applications in the fields of magnetic recording, magnetic field sensors, spintronics and nonvolatile memories. In recent years, the discovery of the spin-orbit torque has opened a spectrum of opportunities to manipulate the magnetization efficiently. This article presents a review of the historical background and recent literature focusing on spin-orbit torques (SOTs), highlighting the most exciting new scientific results and suggesting promising future research directions. It starts with an introduction and overview of the underlying physics of spin-orbit coupling effects in bulk and at interfaces, then describes the use of SOTs to control ferromagnets and antiferromagnets. Finally, we summarize the prospects for the future developments of spintronics devices based on SOTs. Copyright © 2018, The Authors. All rights reserved.

关键词： Torque

来源：评论

学校读者我要写书评

暂无评论

Itinerant quantum critical point with fermion pockets and hot spots

arXiv

引用

arXiv 2018年

作者： Liu, Zi Hong Pan, Gaopei Xu, Xiao Yan Sun, Kai Meng, Zi Yang Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing100190 China School of Physical Sciences University of Chinese Academy of Sciences Beijing100190 China Department of Physics Hong Kong University of Science and Technology Clear Water Bay Hong Kong Department of Physics University of Michigan Ann ArborMI48109 United States CAS Center of Excellence in Topological Quantum Computation School of Physical Sciences University of Chinese Academy of Sciences Beijing100190 China Songshan Lake Materials Laboratory Dongguan Guangdong523808 China

Metallic quantum criticality is among the central theme in the understanding of correlated electronic systems, and converging results between analytical and numerical approaches are still under calling. In this work, we develop state-of-art large scale quantum Monte Carlo simulation technique and systematically investigate the itinerant quantum critical point on a 2D square lattice with antiferromagnetic spin fluctuations at wavevector Q = (π, π) - the problem highly relevant with the non-Fermi-liquid behavior and Fermi pocket and hot spots in the normal state of high-Tc cuprates. System sizes of 60 × 60 × 320 (L × L × Lτ) are comfortably accessed, and the quantum critical scaling behaviors are revealed with unprecedingly high precision. We found that the antiferromagnetic spin fluctuations introduce effective interactions among fermions and the fermions in return render the bare bosonic critical point into a new universality, different from both the bare Ising universality class and the Hertz-Mills-Moriya RPA prediction. At the quantum critical point, a finite anomalous dimension η ∼ 0.125 is observed in the bosonic propagator, and fermions at hot spots evolve into a non-Fermi-liquid. In the antiferromagnetically ordered metallic phase, fermion pockets are observed as energy gap opens up at the hot spots. These results bridge the recent theoretical and numerical developments in metallic quantum criticality and can be served as the stepping stone towards final understanding of the 2D correlated fermions interacting with gapless critical excitations. Copyright © 2018, The Authors. All rights reserved.

关键词： Monte Carlo methods

来源：评论

学校读者我要写书评

暂无评论

Symmetry-enforced self-learning Monte Carlo method applied to the Holstein model

引用

Physical Review B 2018年第4期98卷 041102(R)-041102(R)页

作者： Chuang Chen Xiao Yan Xu Junwei Liu George Batrouni Richard Scalettar Zi Yang Meng Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences Beijing 100190 China School of Physical Sciences University of Chinese Academy of Sciences Beijing 100190 China Department of Physics Hong Kong University of Science and Technology Clear Water Bay Hong Kong China Université Côte d'Azur INPHYNI CNRS 0600 Nice France Beijing Computational Science Research Center Beijing 100193 China MajuLab CNRS-UNS-NUS-NTU International Joint Research Unit UMI 3654 Singapore Centre for Quantum Technologies National University of Singapore 2 Science Drive 3 117542 Singapore Physics Department University of California Davis California 95616 USA CAS Center of Excellence in Topological Quantum Computation and School of Physical Sciences University of Chinese Academy of Sciences Beijing 100190 China

The self-learning Monte Carlo method (SLMC), using a trained effective model to guide Monte Carlo sampling processes, is a powerful general-purpose numerical method recently introduced to speed up simulations in (quantum) many-body systems. In this Rapid Communication, we further improve the efficiency of SLMC by enforcing physical symmetries on the effective model. We demonstrate its effectiveness in the Holstein Hamiltonian, one of the most fundamental many-body descriptions of electron-phonon coupling. Simulations of the Holstein model are notoriously difficult due to a combination of the typical cubic scaling of fermionic Monte Carlo and the presence of extremely long autocorrelation times. Our method addresses both bottlenecks. This enables simulations on large lattices in the most difficult parameter regions, and an evaluation of the critical point for the charge density wave transition at half filling with high precision. We argue that our work opens a research area of quantum Monte Carlo, providing a general procedure to deal with ergodicity in situations involving Hamiltonians with multiple, distinct low-energy states.

关键词： Critical exponents Electron-phonon coupling Strongly correlated systems Machine learning Quantum Monte Carlo

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：