Article
Physics, Multidisciplinary
Kai Li, Jiong-Hao Wang, Yan-Bin Yang, Yong Xu
Summary: Recent theoretical studies suggest that structural disorder can induce a topological insulator from a crystalline material, but experimental observation is challenging. With the experimentally realized randomly positioned Rydberg atoms, studying structural disorder induced topological phase transitions becomes feasible. The research reveals symmetry-protected topological amorphous insulators and structural disorder induced topological phase transition at a single-particle level in an experimentally accessible system.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Tian-Shu Deng, Lei Pan, Yu Chen, Hui Zhai
Summary: This study investigates the stability of Kramers degeneracy and nontrivial topological states under time-reversal symmetry against coupling to the environment. The results show that dissipation can lead to splitting of spectral functions for degenerate states and induce backscattering between counterpropagating edge states, causing the absence of accurate quantization of conductance in the case of the quantum spin Hall effect. The findings have implications for interacting topological phases protected by time-reversal symmetry.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Shang-Qiang Ning, Chenjie Wang, Qing-Rui Wang, Zheng-Cheng Gu
Summary: In this study, the Abelian Chern-Simons theory was used to analyze fermionic SPT phases protected by arbitrary Abelian total symmetry G(f). Compared to bosonic SPT phases, these fermionic phases exhibit new features such as support for gapless Majorana fermion edge modes and the effect of nontrivial symmetry extensions on bosonic SPT phases. This research also sheds light on the realization of intrinsic fSPT phases in interacting fermionic systems.
Article
Materials Science, Multidisciplinary
Thomas Quella
Summary: The study investigates the phase diagram of the SOq(3) quantum group invariant spin-1 bilinear-biquadratic spin chain for real values of q > 1, revealing three distinct phases. The Haldane phase was found to lack twofold degeneracy in the entanglement spectrum, restored through q deformation. The analytical calculations in the limit q -> infinity confirmed the structure of the phase diagram.
Article
Multidisciplinary Sciences
Xu Zhang, Wenjie Jiang, Jinfeng Deng, Ke Wang, Jiachen Chen, Pengfei Zhang, Wenhui Ren, Hang Dong, Shibo Xu, Yu Gao, Feitong Jin, Xuhao Zhu, Qiujiang Guo, Hekang Li, Chao Song, Alexey Gorshkov, Thomas Iadecola, Fangli Liu, Zhe-Xuan Gong, Zhen Wang, Dong-Ling Deng, H. Wang
Summary: This paper reports the observation of a non-equilibrium state of matter, Floquet symmetry-protected topological phases, implemented through digital quantum simulation with programmable superconducting qubits. The researchers observe robust long-lived temporal correlations and subharmonic temporal response for the edge spins.
Article
Physics, Multidisciplinary
Abhishodh Prakash, Juven Wang
Summary: It has been proven that the boundaries of all nontrivial (1 + 1)-dimensional intrinsically fermionic symmetry-protected-topological phases, protected by finite on-site symmetries (unitary or antiunitary), are supersymmetric quantum mechanical systems. This supersymmetry arises as a consequence of the boundary 't Hooft anomaly that classifies the phase, and is distinct from other well-known degeneracies such as Kramers doublets.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Mathematical
Yoshiko Ogata
Summary: The study focuses on SPT phases with on-site finite group G symmetry in two-dimensional Fermion systems, and derives an invariant for classification.
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
Helene Spring, Anton Akhmerov, Daniel Varjas
Summary: In amorphous topological materials, protection of topological surface states is improved due to continuous rotation symmetry, resulting in critical scaling of transport and protection of edge from localization in the topological phase.
Article
Physics, Multidisciplinary
Ruochen Ma, Chong Wang
Summary: In this study, we demonstrate that symmetry-protected topological (SPT) phases can also be applied to average symmetries, where local quenched disorders break the symmetries but restore them upon disorder averaging. We classify and characterize a large class of average SPT phases using a decorated domain wall approach, and show that the boundary states of such phases will almost certainly be long-range entangled. We also develop a theory for generalized average SPT phases based on density matrices and quantum channels, indicating that topological quantum phenomena associated with average symmetries can be as rich as those with exact symmetries.
Article
Materials Science, Multidisciplinary
Chao-Ming Jian, Xiao-Chuan Wu, Yichen Xu, Cenke Xu
Summary: This study explores the physical constructions and boundary properties of various symmetry-protected topological phases involving 1-form symmetries, from one spatial dimension to four spatial dimensions. It also examines anomalies of 3d states of matter and discusses the connection between SPT states with 1-form symmetries and condensed-matter systems in lower dimensions. Additionally, the potential trivial gapped phases of quantum dimer models are explored based on the nature of their corresponding bulk states in higher dimensions.
Article
Mathematics, Applied
Yoshiko Ogata
Summary: This study explores symmetry-protected topological phases in two-dimensional quantum spin systems with specific symmetries, demonstrating the existence of a specific invariant for these phases.
FORUM OF MATHEMATICS PI
(2021)
Article
Physics, Multidisciplinary
Ziteng Wang, Xiangdong Wang, Zhichan Hu, Domenico Bongiovanni, Dario Jukic, Liqin Tang, Daohong Song, Roberto Morandotti, Zhigang Chen, Hrvoje Buljan
Summary: Some topological boundary states are protected by sub-symmetry, even if the full symmetry and topological invariant are destroyed. By introducing a weaker sub-symmetry requirement, researchers find that the nature of boundary state protection is more complex than previously believed. Experimental demonstrations in photonic lattices show the sub-symmetry protection of topological states and the resolution of debates on the higher-order topological nature of corner states in breathing kagome lattices. These findings have implications beyond photonics and can be applied to explore symmetry-protected topological phases in different physical contexts.
Article
Physics, Mathematical
Yoshiko Ogata
Summary: This paper focuses on the classification of SPT phases using Z(2) indices, introducing an index for unique gapped ground state phases with reflection symmetry and completing the generalization problem of the index by Pollmann et al. It is shown that the index is an invariant of the C-1 classification.
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Carolyn Zhang
Summary: We propose a framework to classify LPUs with internal, unitary symmetries in d dimensions using (d - 1) dimensional flux insertion operators that can be easily computed. By applying this framework, we derive formulas for topological invariants of LPUs that prepare or entangle SPTs. These formulas can also serve as edge invariants for Floquet topological phases in (d + 1) dimensions that pump d-dimensional SPTs. For 1D SPT entanglers and certain higher dimensional SPT entanglers, our formulas are completely closed-form.
Article
Physics, Multidisciplinary
Felix Gerken, Thore Posske, Shaul Mukamel, Michael Thorwart
Summary: We develop a microscopic theory to study the two-dimensional spectroscopy of one-dimensional topological superconductors. By considering a ring geometry with periodic boundary conditions, the energy-specific differences caused by topologically protected or trivial boundary modes are bypassed. Numerical and analytical results show that the cross-peak structure in the 2D spectra carries unique signatures of the topological phases of the chain. Our work reveals the potential of 2D spectroscopy in identifying topological phases in bulk properties.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Wan-Jun Su, Guang-Zheng Ye, Ya-Dong Wu, Zhen-Biao Yang, Barry C. Sanders
Summary: In this study, we propose a scheme to achieve nuclear-nuclear indirect interactions mediated by a mechanically driven nitrogen-vacancy (NV) center in a diamond. We demonstrate experimental results of two-qubit entangling gates and quantum-state transfer, and find that the scheme is robust against decoherence caused by coupling between the NV center (nuclear spins) and the environment, and insensitive to fluctuating positions of the nuclear spins and the NV center. This scheme provides a general blueprint for multi-nuclear-spin gates and multi-party communication.
COMMUNICATIONS IN THEORETICAL PHYSICS
(2022)
Article
Optics
Shou-Bang Yang, Wen Ning, Ri-Hua Zheng, Zhen-Biao Yang, Shi-Biao Zheng
Summary: This paper proposes an experimentally feasible scheme to achieve deterministic entanglement swapping in hybrid systems with discrete and continuous variables. The scheme involves preparing entangled states, performing a Bell-state analysis, and projecting the qubits.
Article
Physics, Multidisciplinary
Ri-Hua Zheng, Wen Ning, Zhen-Biao Yang, Yan Xia, Shi-Biao Zheng
Summary: This article presents a method for dynamical control in three-level open systems and demonstrates its implementation in an experiment with a superconducting qutrit. The results show that in a Markovian environment, the populations or coherence of the system can still strictly follow the preset evolution paths for a relatively long time (3 μs). This experiment is the first to precisely control the Markovian dynamics of three-level open systems, providing a solid foundation for future dynamical control in multiple open systems. An immediate application of this technique is to stabilize the energy of quantum batteries.
NEW JOURNAL OF PHYSICS
(2022)
Article
Multidisciplinary Sciences
Zhongchu Ni, Sai Li, Xiaowei Deng, Yanyan Cai, Libo Zhang, Weiting Wang, Zhen-Biao Yang, Haifeng Yu, Fei Yan, Song Liu, Chang-Ling Zou, Luyan Sun, Shi-Biao Zheng, Yuan Xu, Dapeng Yu
Summary: Quantum error correction (QEC) protects logical qubits by using a large Hilbert space with redundancy to detect and correct errors in real time. In this study, a QEC procedure was demonstrated in a circuit quantum electrodynamics architecture, where a logical qubit was encoded in photon-number states of a microwave cavity and coupled to an auxiliary superconducting qubit. By applying a tailored frequency comb pulse, error syndrome was extracted and error correction was performed, exceeding the break-even point by about 16% lifetime enhancement. This work illustrates the potential of hardware-efficient discrete-variable encodings for fault-tolerant quantum computation.
Article
Physics, Multidisciplinary
Jingwen Yang, Zhicheng Shi, Zhen-Biao Yang, Li-tuo Shen, Shi-Biao Zheng
Summary: Quantum phase transition and entanglement in the Rabi model with squeezed light were investigated. A special unitary-transformation method was found to remove nonintegrable squeezing and counter-rotating wave interactions when the qubit frequency is close to the field frequency. The analytical ground state agrees well with the numerical solution. It was demonstrated that the ground state exhibits a first-order quantum phase transition induced linearly by the squeezed light. This quantum phase transition does not require multiple qubits or an infinite ratio of qubit frequency to field frequency, addressing a critical problem in the theory and experiment of the Rabi model. As the qubit-field coupling strength increases, the ground-state entanglement reaches its maximum value at the critical point.
Article
Physics, Multidisciplinary
Xin Zhu, Jia-Hao Lue, Wen Ning, Fan Wu, Li-Tuo Shen, Zhen-Biao Yang, Shi-Biao Zheng
Summary: This study generalizes the dynamic framework for criticality-enhanced quantum sensing by the quantum Rabi model to its anisotropic counterpart and derives the corresponding analytical expressions for the quantum Fisher information. The results show that the contributions of the rotating-wave and counterrotating-wave interaction terms are symmetric at the limit of the infinite ratio of qubit frequency to field frequency, and the quantum Fisher information reaches a maximum for the isotropic QRM. At finite frequency scaling, the study analytically derives the inverted variance of higher-order correction and finds that it is more affected by the rotating-wave coupling than by the counterrotating-wave coupling.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2023)
Article
Quantum Science & Technology
Xin-Jie Huang, Pei-Rong Han, Wen Ning, Shou-Bang Yang, Xin Zhu, Jia-Hao Lue, Ri-Hua Zheng, Hekang Li, Zhen-Biao Yang, Kai Xu, Chui-Ping Yang, Qi-Cheng Wu, Dongning Zheng, Heng Fan, Shi-Biao Zheng
Summary: Quantum entanglement between an interfering particle and a detector for acquiring the which-path information plays a central role for enforcing Bohr's complementarity principle. However, the quantitative relation between this entanglement and the fringe visibility remains untouched upon for an initial mixed state. Here we find an equality for quantifying this relation. Our equality characterizes how well the interference pattern can be preserved when an interfering particle, initially carrying a definite amount of coherence, is entangled, to a certain degree, with a which-path detector. This equality provides a connection between entanglement and interference in the unified framework of coherence, revealing the quantitative entanglement-interference complementarity. We experimentally demonstrate this relation with a superconducting circuit, where a resonator serves as a which-path detector for an interfering qubit. The measured fringe visibility of the qubit's Ramsey signal and the qubit-resonator entanglement exhibit a complementary relation, in well agreement with the theoretical prediction.
NPJ QUANTUM INFORMATION
(2023)
Article
Chemistry, Physical
Peng-Jie Guo, Zheng-Xin Liu, Zhong-Yi Lu
Summary: In this work, we demonstrate the realization of the quantum anomalous Hall effect in antiferromagnetic materials, which has never been reported before. By proposing a four-band lattice model with static antiferromagnetic order, we show that the quantum anomalous Hall effect can be found in antiferromagnetic materials. Additionally, we provide evidence that a monolayer CrO can be transformed from an antiferromagnetic Weyl semimetal to an antiferromagnetic quantum anomalous Hall insulator by applying strain, based on symmetry analysis and electronic structure calculations.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Optics
Ling-Shan Lin, Hao-Long Zhang, Zhen-Biao Yang
Summary: Geometry, as a fundamental concept, is widely applied in understanding physical phenomena. In the field of quantum mechanics, the quantum geometric tensor (QGT) is used to characterize the relationship between geometry and the quantum state of a system. Previous research has focused on extracting the quantum metric tensor (QMT) using discrete variables, but there is a lack of research using continuous variables. In this study, a method to extract the QMT of a continuous variable system, specifically a cat-qubit, is proposed by constructing a Kerr nonlinear parametric oscillator (KNPO). This method opens the door for exploring geometry in continuous variable systems.
Article
Quantum Science & Technology
Bi-Yao Wang, Hao-Long Zhang, Shou-Bang Yang, Fan Wu, Zhen-Biao Yang, Shi-Biao Zheng
Summary: This paper proposes a scheme for measuring topological properties in a two-photon-driven Kerr-nonlinear (KNR) resonator subjected to a single-photon modulation. The topological properties are revealed through the observation of the Berry curvature and the first Chern number as a nonadiabatic response of the physical observable to the change rate of the control parameter. The parameter manifold constructed from the system's Hamiltonian indicates a topological transition when the degeneracy crosses the manifold. The scheme, utilizing continuous variable states in mesoscopic systems, offers a new perspective for exploring the geometry and topology of complex systems.
ADVANCED QUANTUM TECHNOLOGIES
(2023)
Article
Quantum Science & Technology
Wen Ning, Ri-Hua Zheng, Yan Xia, Kai Xu, Hekang Li, Dongning Zheng, Heng Fan, Fan Wu, Zhen-Biao Yang, Shi-Biao Zheng
Summary: This study reveals a more fundamental and universal interference behavior beyond Zitterbewegung in phase space for Dirac particles, which is confirmed by both numerical simulation and on-chip experiment. This discovery is of fundamental importance in science and holds potential applications in quantum technology.
NPJ QUANTUM INFORMATION
(2023)
Article
Materials Science, Multidisciplinary
Arkya Chatterjee, Xiao-Gang Wen
Summary: Symmetry is usually defined by transformations described by a (higher) group. However, symmetries can also be described by an algebra of local symmetric operators, which directly affect the properties of the system. This paper introduces the concept of transparent patch operators, a special class of extended operators within the algebra of local symmetric operators, which reveal the selection sectors and corresponding symmetries. The algebra of these transparent patch operators in n-dimensional space gives rise to a nondegenerate braided fusion n-category, providing a unified and systematic description of generalized symmetries.
Article
Materials Science, Multidisciplinary
Salvatore D. Pace, Xiao-Gang Wen
Summary: This study investigates a compact U-kappa(1) gauge theory in 3 + 1 dimensions with a general 2π-quantized topological term and a symmetric matrix K. It shows that at energies below the gauge charges' gaps but above the monopoles' gaps, the theory exhibits a compact Z(k1)((1)) x Z(k2)((1)) x ... 1 symmetry.
Article
Materials Science, Multidisciplinary
Yan-Guang Yue, Zheng-Xin Liu
Summary: This work proposes a scenario to realize the Hopf term in lattice models by tuning the coupling between spins and Dirac fermions. By utilizing the orbital degrees of freedom, a theta = 2 pi Hopf term is successfully generated for the spin system on the honeycomb lattice.
Article
Materials Science, Multidisciplinary
Shang-Qiang Ning, Zheng-Xin Liu, Peng Ye
Summary: This paper establishes a topological-field-theoretical framework approach for 3D topological orders, which leads to a systematic characterization and classification of symmetry fractionalization. It successfully computes topologically distinct types of fractional symmetry charges carried by particles and their statistical phases of braiding processes among loop excitations and external symmetry fluxes.
