检索结果-内蒙古大学图书馆

Coherent-cluster-state generation in networks of degenerate optical parametric oscillators

Physical Review A 2023年第2期108卷 023704-023704页

作者： Zheng-Yang Zhou Clemens Gneiting J. Q. You Franco Nori Key Laboratory of Optical Field Manipulation of Zhejiang Province Department of Physics ZSTU Hangzhou 310018 China Theoretical Quantum Physics Laboratory Cluster for Pioneering Research RIKEN Wakoshi Saitama 351-0198 Japan Beijing Computational Science Research Center Beijing 100094 China Center for Quantum Computing RIKEN Wakoshi Saitama 351-0198 Japan Interdisciplinary Center of Quantum Information State Key Laboratory of Modern Optical Instrumentation Zhejiang Province Key Laboratory of Quantum Technology and Device School of Physics Zhejiang University Hangzhou 310027 China Physics Department University of Michigan Ann Arbor Michigan 48109-1040 USA

Cluster states are versatile quantum resources and an essential building block for measurement-based quantum computing. The possibility to generate cluster states in specific systems may thus serve as an indicator regarding if and to what extent these systems can be harnessed for quantum technologies and quantum information processing in particular. Here, we apply this analysis to networks of degenerate optical parametric oscillators (DOPOs), also called coherent Ising machines (CIMs). CIMs are distinguished by their highly flexible coupling capabilities, which makes it possible to use them, e.g., to emulate large spin systems. As CIMs typically operate with coherent states (and superpositions thereof), it is natural to consider cluster states formed by superpositions of coherent states, i.e., coherent cluster states. As we show, such coherent cluster states can, under ideal conditions, be generated in DOPO networks with the help of beam splitters and classical pumps. Our subsequent numerical analysis provides the minimum requirements for the generation of coherent cluster states under realistic conditions. Moreover, we discuss how nonequilibrium pumps can improve the generation of coherent cluster states. In order to assess the quality of the cluster-state generation, we map the generated states to an effective spin space using modular variables, which allows us to apply entanglement criteria tailored for spin-based cluster states.

关键词： Open quantum systems quantum optics Fiber lasers

来源：评论

学校读者我要写书评

暂无评论

quantum dynamics on a lossy non-Hermitian lattice

arXiv

引用

arXiv 2020年

作者： Wang, Li Liu, Qing Zhang, Yunbo Institute of Theoretical Physics State Key Laboratory of Quantum Optics and Quantum Optics Devices Collaborative Innovation Center of Extreme Optics Shanxi University Taiyuan030006 China Key Laboratory of Optical Field Manipulation of Zhejiang Province Physics Department Zhejiang Sci-Tech University Hangzhou310018 China

We investigate quantum dynamics of a quantum walker on a finite bipartite non-Hermitian lattice, in which the particle can leak out with certain rate whenever it visits one of the two sublattices. quantum walker initially located on one of the non-leaky sites will finally totally disappear after a length of evolution time and the distribution of decay probability on each unit cell is obtained. In one regime, the resultant distribution shows an expected decreasing behavior as the distance from the initial site increases. However, in the other regime, we find that the resultant distribution of local decay probability is very counterintuitive, in which a relatively high population of decay probability appears on the edge unit cell which is the farthest from the starting point of the quantum walker. We then analyze the energy spectrum of the non-Hermitian lattice with pure loss, and find that the intriguing behavior of the resultant decay probability distribution is intimately related to the existence and specific property of edge states, which are topologically protected and can be well predicted by the non-Bloch winding number. The exotic dynamics may be observed experimentally with arrays of coupled resonator optical waveguides. Copyright © 2020, The Authors. All rights reserved.

关键词： quantum theory

来源：评论

学校读者我要写书评

暂无评论

Molecular state in a spin–orbital-angular-momentum coupled Fermi gas

引用

Physical Review A 2022年第4期106卷 043302-043302页

作者： Yiwen Han Shi-Guo Peng Ke-Ji Chen Wei Yi Chinese Academy of Sciences Key Laboratory of Quantum Information University of Science and Technology of China Hefei 230026 China State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Innovation Academy for Precision Measurement Science and Technology Chinese Academy of Sciences Wuhan 430071 China Key Laboratory of Optical Field Manipulation of Zhejiang Province and Physics Department of Zhejiang Sci-Tech University Hangzhou 310018 China Chinese Academy of Sciences Center For Excellence in Quantum Information and Quantum Physics Hefei 230026 China

We study the two-body bound states in a spin-orbital-angular-momentum (SOAM) coupled quantum gas of fermions within a tightly confined ring geometry in two dimensions. Two different configurations are considered: an attractive s-wave interaction exists between two spin species that are SOAM coupled and an atom with SOAM coupled internal spins interacts state selectively with another atom. For both cases, we identify the condition for the emergence of molecular states with finite orbital angular momenta. These molecular states with quantized orbital angular momenta correspond to the SOAM-coupling-induced vortices in the corresponding Fermi superfluid. We propose to detect the molecules through Raman spectroscopy with Laguerre-Gaussian lasers. As the molecular states can form above the superfluid temperature, they offer an experimentally more accessible route toward the study of the underlying pairing mechanism under SOAM coupling.

关键词： Angular momentum of light Cold atoms & matter waves Fermi gases Spin-orbit coupling Synthetic gauge fields Atomic gases

来源：评论

学校读者我要写书评

暂无评论

Two atoms in a harmonic trap with spin-orbital-angular-momentum coupling

arXiv

引用

arXiv 2024年

作者： Chen, Xiao-Long Chen, Aixi Peng, Shi-Guo Department of Physics Zhejiang Sci-Tech University Hangzhou310018 China Zhejiang Key Laboratory of Quantum State Control and Optical Field Manipulation Zhejiang Sci-Tech University Hangzhou310018 China State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Innovation Academy for Precision Measurement Science and Technology Chinese Academy of Sciences Wuhan430071 China

We study the problem of two harmonically trapped atoms in the presence of spin-orbital-angular-momentum (SOAM) coupling. The two-body energy spectrum is numerically calculated by utilizing the exact diagonalization method. We analyze how the degeneracy of energy levels is lifted under the interplay between the interatomic interaction and SOAM coupling. The exact numerical results show excellent agreement with that of perturbation theory in the weak-interaction limit as well as that in the absence of SOAM coupling. The properties of correlations between the two atoms are also discussed with respect to the interaction strength. The findings in this paper may provide valuable insights into few-body physics subjected to SOAM coupling and the possible experimental detection of spectrum functions in many-body systems, such as radiofrequency spectroscopy. © 2024, CC BY.

关键词： Radiofrequency spectroscopy

来源：评论

学校读者我要写书评

暂无评论

Bound states in one-dimensional systems with colored noise

arXiv

引用

arXiv 2024年

作者： Wei, Xingbo Feng, Kewei Yi, Tian-Cheng Liu, Tong Xianlong, Gao Zhang, Yunbo Zhejiang Key Laboratory of Quantum State Control and Optical Field Manipulation Department of Physics Zhejiang Sci-Tech University Hangzhou310018 China Department of Applied Physics School of Science Nanjing University of Posts and Telecommunications Nanjing210003 China Department of Physics Zhejiang Normal University Jinhua321004 China

We investigate the phase transitions in a one-dimensional system with colored noise. Previous studies indicated that the phase diagram of this system included extended and disorder-induced localized phases. However, by studying the properties of wave functions, we find that this phase diagram can be further refined, revealing the existence of a bound phase for the large potential amplitude W and noise control parameter α. In the bound phase, the wave function cannot extend throughout the entire chain, tails decay faster than exponentially and its distribution expands as the system size increases. By adjusting the potential amplitude to induce a transition from the extended phase to the bound phase, we find that bound states coexist with extended states in the spectrum. In contrast, when the system transitions from the Anderson localized phase to the bound phase, we do not observe the obvious coexistence of Anderson localized and bound states. Finally, by performing the time evolution, we find that the dynamic transition point of the bound phase is inconsistent with the static one for large α. Copyright © 2024, The Authors. All rights reserved.

关键词： Wave functions

来源：评论

学校读者我要写书评

暂无评论

Angular topological superfluid and topological vortex in an ultracold Fermi gas

引用

Physical Review Research 2022年第3期4卷 033023-033023页

作者： Ke-Ji Chen Fan Wu Lianyi He Wei Yi Key Laboratory of Optical Field Manipulation of Zhejiang Province and Physics Department of Zhejiang Sci-Tech University Hangzhou 310018 China Fujian Key Laboratory of Quantum Information and Quantum Optics College of Physics and Information Engineering Fuzhou University Fuzhou Fujian 350108 China Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics Tsinghua University Beijing 100084 China CAS Key Laboratory of Quantum Information University of Science and Technology of China Hefei 230026 China CAS Center For Excellence in Quantum Information and Quantum Physics Hefei 230026 China

We show that pairing in an ultracold Fermi gas under spin-orbital-angular-momentum coupling (SOAMC) can acquire topological characters encoded in the quantized angular degrees of freedom. The resulting topological superfluid is the angular analog of its counterpart in a one-dimensional Fermi gas with spin-orbit coupling, but characterized by a Zak phase defined in the angular-momentum space. Upon tuning the SOAMC parameters, a topological phase transition occurs, which is accompanied by the closing of the quasiparticle excitation gap. Remarkably, a topological vortex state can also be stabilized by deforming the Fermi surface, which is topologically nontrivial in both the coordinate and angular-momentum space, offering interesting potentials for applications in quantum information and quantum control. We discuss how the topological phase transition and the exotic vortex state can be detected experimentally.

关键词： Fermionic condensates Geometric & topological phases Synthetic gauge fields Superfluids Ultracold gases

来源：评论

学校读者我要写书评

暂无评论

Reentrant Localization Transitions in a Topological Anderson Insulator: A Study of a Generalized Su-Schrieffer-Heeger Quasicrystal

arXiv

引用

arXiv 2023年

作者： Lu, Zhanpeng Zhang, Yunbo Xu, Zhihao 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 Collaborative Innovation Center of Extreme Optics Shanxi University Taiyuan030006 China

We study the topology and localization properties of a generalized Su-Schrieffer-Heeger (SSH) model with a quasi-periodic modulated hopping. It is found that the interplay of off-diagonal quasi-periodic modulations can induce topological Anderson insulator (TAI) phases and reentrant topological Anderson insulator (RTAI), and the topological phase boundaries can be uncovered by the divergence of the localization length of the zero-energy mode. In contrast to the conventional case that the TAI regime emerges in a finite range with the increase of disorder, the TAI and RTAI are robust against arbitrary modulation amplitude for our system. Furthermore, we find that the TAI and RTAI can induce the emergence of reentrant localization transitions. Such an interesting connection between the reentrant localization transition and the TAI/RTAI can be detected from the wave-packet dynamics in cold atom systems by adopting the technique of momentum-lattice engineering. © 2023, CC BY.

关键词： Topology

来源：评论

学校读者我要写书评

暂无评论

Non-thermal dynamics in a spin-1/2 lattice Schwinger model

arXiv

引用

arXiv 2023年

作者： Gao, Chunping Tang, Zheng Zhu, Fei Zhang, Yunbo Pu, Han Chen, Li 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 Physics Department Zhejiang Sci-Tech University Hangzhou310018 China Department of Physics and Astronomy Rice Center for Quantum Materials Rice University HoustonTX77005 United States

Local gauge symmetry is intriguing for the study of quantum thermalization breaking. For example, in the high-spin lattice Schwinger model (LSM), the local U(1) gauge symmetry underlies the disorder-free many-body localization (MBL) dynamics of matter fields. This mechanism, however, would not work in a spin-1/2 LSM due to the absence of electric energy in the Hamiltonian. In this paper, we show that the spin-1/2 LSM can also exhibit disorder-free MBL dynamics, as well as entropy prethermalization, by introducing a four-fermion interaction into the system. The interplay between the fermion interaction and U(1) gauge symmetry endows the gauge fields with an effectively disordered potential which is responsible for the thermalization breaking. It induces anomalous (i.e., non-thermal) behaviors in the long-time evolution of such quantities as local observables, entanglement entropy, and correlation functions. Our work offers a new platform to explore emergent non-thermal dynamics in state-of-the-art quantum simulators with gauge symmetries. Copyright © 2023, The Authors. All rights reserved.

关键词： quantum entanglement

来源：评论

学校读者我要写书评

暂无评论

Erratum to: Collisional dynamics of symmetric two-dimensional quantum droplets

引用

Frontiers of Physics 2022年第6期17卷 1-1页

作者： Hu Yanming Fei Yifan Chen Xiao-Long Zhang Yunbo Institute of Theoretical Physics and State Key Laboratory of Quantum Optics and Quantum Optics Devices Shanxi University Taiyuan 030006 China Department of Physics and Key Laboratory of Optical Field Manipulation of Zhejiang Province Zhejiang Sci-Tech University Hangzhou 310018 China

来源：评论

学校读者我要写书评

暂无评论

Ferroelectricity-Driven Metallicity and Magnetic Skyrmions in van der Waals Cr2Ge2Te6/Hf2Ge2Te6 Multiferroic Heterostructure

arXiv

引用

arXiv 2024年

作者： Chen, Zheng Hu, Hongliang Wu, Xiaoping Zhang, Wenjun Li, Ping Song, Changsheng Zhejiang Key Laboratory of Quantum State Control and Optical Field Manipulation Department of Physics Zhejiang Sci-Tech University Hangzhou310018 China College of Physics and Information Engineering Shanxi Normal University Taiyuan030031 China College of Science Xinjiang Institute of Technology Xinjiang735400 China Longgang Institute of Zhejiang Sci-Tech University Wenzhou China

Two-dimensional (2D) multiferroic heterostructures present a promising platform for advanced spin devices by leveraging the coexisting ferromagnetic (FM) and ferroelectric (FE) orders. Through first-principles calculations and atomistic simulations, we reveal non-volatile control of metallicity and topological spin textures in the Cr2Ge2Te6/Hf2Ge2Te6 (CGT/HGT) heterostructure. Notably, manipulating ferroelectric polarization in HGT significantly modulates the magnetic anisotropy energy (MAE) and Dzyaloshinskii-Moriya interaction (DMI) of CGT/HGT, reversing the easy magnetization axis from in-plane to out-of-plane. By analyzing the atomic-resolved SOC energy (∆Esoc), it is found that the cause of the change comes from the Fert-Levy mechanism. Additionally, this polarization control enables the creation and annihilation of bimerons and skyrmions, with interlayer sliding further altering magnetic ordering. Our findings offer valuable insights into magnetoelectric coupling and spin texture manipulation in 2D magnets, highlighting their potential for next-generation spintronic and memory devices. Copyright © 2024, The Authors. All rights reserved.

关键词： Van der Waals forces

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：