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Chern numbers are gaining traction as they characterize topological phases in various physical systems. However, the resilience of the system topology to external perturbations makes it challenging to experimentally investigate transitions…

Quantum Physics · Physics 2022-11-28 Junghyun Lee , Keigo Arai , Huiliang Zhang , Mark J. H. Ku , Ronald L. Walsworth

Local topological markers have proven to be a valuable tool for investigating systems with topologically non-trivial bands. Due to their local nature, such markers can treat translationally invariant systems and spatially inhomogeneous…

Quantum Gases · Physics 2021-04-28 Joseph Sykes , Ryan Barnett

We investigate how topological Chern numbers can be defined when single-particle states hybridize with continua. We do so exemplarily in a bosonic Haldane model at zero temperature with an additional on-site decay of one boson into two and…

Mesoscale and Nanoscale Physics · Physics 2025-07-16 B. Hawashin , J. Sirker , G. S. Uhrig

A system having macroscopic patches in different topological phases have no well-defined global topological invariant. To treat such a case, the quantities labeling different areas of the sample according to their topological state are…

Mesoscale and Nanoscale Physics · Physics 2023-04-27 A. A. Markov , D. B. Golovanova , A. R. Yavorsky , A. N. Rubtsov

Topological properties of Harper and generalized Fibonacci chains are studied in crystalline cases, i.e., for rational values of the modulation frequency. The Harper and Fibonacci crystals at fixed frequency are connected by an…

Mesoscale and Nanoscale Physics · Physics 2018-04-17 Guy Amit , Itzhack Dana

A family of semiconductors called as Chern band insulator are shown to host exciton bands with non-zero topological Chern integers and chiral exciton edge modes. Using a prototypical two-band Chern insulator model, we calculate a…

Mesoscale and Nanoscale Physics · Physics 2017-10-11 Ke Chen , Ryuichi Shindou

The Chern number is a crucial topological invariant for distinguishing the phases of Chern insulators. Here we find that for Chern insulators with inversion symmetry, the Chern number alone is insufficient to fully characterize their…

Mesoscale and Nanoscale Physics · Physics 2024-10-01 Yu-Hao Wan , Peng-Yi Liu , Qing-Feng Sun

The organization of the electrons in the ground state is classified by means of topological invariants, defined as global properties of the wavefunction. Here we address the Chern number of a two-dimensional insulator and we show that the…

Strongly Correlated Electrons · Physics 2012-01-23 Raffaello Bianco , Raffaele Resta

Quasi-periodic quantum spin chains were recently found to support many topological phases in the finite magnetization sectors. They can simulate strong topological phases from class A in arbitrary dimension that are characterized by first…

Mesoscale and Nanoscale Physics · Physics 2020-10-14 Yifei Liu , Emil Prodan

Chern insulators are band insulators which exhibit a gap in the bulk and gapless excitations in the edge. Detection of Chern insulators is a serious challenge in cold atoms since the Hall transport measurements are technically unrealistic…

Mesoscale and Nanoscale Physics · Physics 2013-09-30 Xiong-Jun Liu , K. T. Law , T. K. Ng , Patrick A. Lee

Lattice models forming bands with higher Chern number offer an intriguing possibility for new phases of matter with no analogue in continuum Landau levels. Here, we establish the existence of a number of new bulk insulating states at…

Strongly Correlated Electrons · Physics 2012-11-06 Zhao Liu , Emil J. Bergholtz , Heng Fan , Andreas M. Laeuchli

As first demonstrated by the characterization of the quantum Hall effect by the Chern number, topology provides a guiding principle to realize robust properties of condensed matter systems immune to the existence of disorder. The…

Mesoscale and Nanoscale Physics · Physics 2023-08-01 Kazuki Sone , Motohiko Ezawa , Yuto Ashida , Nobuyuki Yoshioka , Takahiro Sagawa

Two-dimensional lattice models subjected to an external effective magnetic field can form nontrivial band topologies characterized by nonzero integer band Chern numbers. In this Letter, we investigate such a lattice model originating from…

Strongly Correlated Electrons · Physics 2013-11-01 Dong Wang , Zhao Liu , Junpeng Cao , Heng Fan

Here we study the systematic evolution of the topological properties of a Chern insulator in presence of an electronic dispersion that can be tuned smoothly from being Dirac-like till a semi-Dirac one and beyond. The band structure under…

Mesoscale and Nanoscale Physics · Physics 2022-03-31 Sayan Mondal , Priyadarshini Kapri , Bashab Dey , Tarun Kanti Ghosh , Saurabh Basu

We investigate the topological phase transition with large Chern number in a coupled layer system. The topological transitions between different topological superfluids can be realized by controlling the binding energy, interlay tunneling…

Quantum Gases · Physics 2015-04-29 Beibing Huang , Jeffrey Chun Fai Chan , Ming Gong

We introduce a novel gauge-invariant, quantized interband index in two-dimensional (2D) multiband systems. It provides a bulk topological classification of a submanifold of parameter space (e.g., an electron valley in a Brillouin zone), and…

Mesoscale and Nanoscale Physics · Physics 2023-08-17 Tharindu Fernando , Ting Cao

The identification of the topological invariant of a topological system is crucial in experiments. However, due to the inherent non-Hermitian features, such determination is notably challenging in non-Hermitian systems. Here, we propose…

Mesoscale and Nanoscale Physics · Physics 2024-01-30 Hongfang Liu , Ming Lu , Shengdu Chai , Zhi-Qiang Zhang , Hua Jiang

The use of topological invariants to describe geometric phases of quantum matter has become an essential tool in modern solid state physics. The first instance of this paradigmatic trend can be traced to the study of the quantum Hall…

Mathematical Physics · Physics 2017-05-19 Domenico Monaco

Recent theoretical works have demonstrated various robust Abelian and non-Abelian fractional topological phases in lattice models with topological flat bands carrying Chern number C=1. Here we study hard-core bosons and interacting fermions…

Strongly Correlated Electrons · Physics 2012-11-07 Yi-Fei Wang , Hong Yao , Chang-De Gong , D. N. Sheng

Topology has appeared in different physical contexts. The most prominent application is topologically protected edge transport in condensed matter physics. The Chern number, the topological invariant of gapped Bloch Hamiltonians, is an…

Mesoscale and Nanoscale Physics · Physics 2018-01-24 Thomas Fösel , Vittorio Peano , Florian Marquardt