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Related papers: Measuring Chern numbers in Hofstadter strips

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We detect the topological properties of Chern insulators with strong Coulomb interactions by use of cluster perturbation theory and variational cluster approach. The common scheme in previous studies only involves the calculation of the…

Strongly Correlated Electrons · Physics 2019-07-30 Zhao-Long Gu , Kai Li , Jian-Xin Li

We establish the theory of critical transport in amorphous Chern insulators and show that it lies beyond the current paradigm of topological criticality epitomized by the quantum Hall transitions. We consider models of Chern insulators on…

Mesoscale and Nanoscale Physics · Physics 2020-12-08 Moein N. Ivaki , Isac Sahlberg , Teemu Ojanen

We revisit the problem of classifying topological band structures in non-Hermitian systems. Recently, a solution has been proposed, which is based on redefining the notion of energy band gap in two different ways, leading to the so-called…

Mathematical Physics · Physics 2020-05-20 Charles C. Wojcik , Xiao-Qi Sun , Tomáš Bzdušek , Shanhui Fan

The Chern number is often used to distinguish between different topological phases of matter in two-dimensional electron systems. A fast and efficient coupling-matrix method is designed to calculate the Chern number in finite crystalline…

Disordered Systems and Neural Networks · Physics 2018-09-13 Y. F. Zhang , Y. Y. Yang , Yan Ju , L. Sheng , D. N. Sheng , R. Shen , D. Y. Xing

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

Topology is central to understanding and engineering materials that display robust physical phenomena immune to imperfections. Different topological phases of matter are characterised by topological invariants. In energy-conserving…

The properties of the Hofstadter butterfly, a fractal, self similar spectrum of a two dimensional electron gas, are studied in the case where the system is additionally illuminated with monochromatic light. This is accomplished by applying…

Mesoscale and Nanoscale Physics · Physics 2019-10-23 Martin Wackerl , Paul Wenk , John Schliemann

Topological quantum phases of matter have been a topic of intense interest in contemporary condensed matter physics. Extensive efforts are devoted to investigate various exotic properties of topological matters including topological…

Strongly Correlated Electrons · Physics 2015-11-25 Woo-Ram Lee , Kwon Park

The quantization of transport and its resilience to backscattering are key features for leveraging topological matter in applications that demand stringent noise mitigation, such as metrology and quantum information processing. Due to the…

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

Topological phases of matter are the center of much current interest, with promising potential applications in, e.g., topologically-protected transport and quantum computing. Traditionally such states are prepared by tuning the system…

Quantum Gases · Physics 2020-03-17 Gal Shavit , Moshe Goldstein

The Hofstadter model is a popular choice for theorists investigating the fractional quantum Hall effect on lattices, due to its simplicity, infinite selection of topological flat bands, and increasing applicability to real materials. In…

Strongly Correlated Electrons · Physics 2021-09-09 Bartholomew Andrews , Titus Neupert , Gunnar Möller

We present an approach for the calculation of the $\mathbb{Z}_2$ topological invariant in non-crystalline two-dimensional quantum spin Hall insulators. While topological invariants were originally mathematically introduced for crystalline…

Mesoscale and Nanoscale Physics · Physics 2023-02-28 Roberta Favata , Antimo Marrazzo

Uncovering topologically nontrivial states in nature is an intriguing and important issue in recent years. While most studies are based on the topological band insulators, the topological state in strongly correlated low-dimensional systems…

Strongly Correlated Electrons · Physics 2015-03-18 Hai-Ping Hu , Chen Cheng , Hong-Gang Luo , Shu Chen

We report the theoretical discovery of a large class of 2D tight-binding models containing nearly-flat bands with nonzero Chern numbers. In contrast with previous studies, where nonlocal hoppings are usually required, the Hamiltonians of…

Strongly Correlated Electrons · Physics 2011-06-07 Kai Sun , Zheng-Cheng Gu , Hosho Katsura , S. Das Sarma

Topological phases of gapped one-particle Hamiltonians with (anti)-unitary symmetries are classified by strong topological invariants according to the Altland-Zirnbauer table. Those indices are still well-defined in the regime of strong…

Mathematical Physics · Physics 2024-10-30 Tom Stoiber

We consider topologically non-trivial interface Hamiltonians, which find several applications in materials science and geophysical fluid flows. The non-trivial topology manifests itself in the existence of topologically protected,…

Mathematical Physics · Physics 2021-01-05 Guillaume Bal

We prove that a rational linear combination of Chern numbers is an oriented diffeomorphism invariant of smooth complex projective varieties if and only if it is a linear combination of the Euler and Pontryagin numbers. In dimension at least…

Geometric Topology · Mathematics 2011-11-24 D. Kotschick

In this paper, the influence of the quasidisorder on a two-dimensional system is studied. We find that there exists a topological phase transition accompanied by a transverse Anderson localization. The topological properties are…

Disordered Systems and Neural Networks · Physics 2023-08-09 Shujie Cheng , Reza Asgari , Gao Xianlong

Topological phases have greatly improved our understanding of modern conception of phases of matter that go beyond the paradigm of symmetry breaking and are not described by local order parameters. Instead, characterization of topological…

Quantum Physics · Physics 2022-08-12 Zhihuang Luo , Wenzhao Zhang , Xinfang Nie , Dawei Lu