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Related papers: Large Chern numbers in a dissipative dice model

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One dimensional topological insulators are characterized by edge states with exponentially small energies. According to one generalization of topological phases to non-Hermitian systems, a finite system in a non-trivial topological phase…

Quantum Physics · Physics 2017-12-06 Lorenzo Campos Venuti , Zhengzhi Ma , Hubert Saleur , Stephan Haas

We analyze the non-Hermitian Haldane model where the spin-orbit interaction is made non-Hermitian. The Dirac mass becomes complex. We propose to realize it by an $LC$ circuit with operational amplifiers. A topological phase transition is…

Mesoscale and Nanoscale Physics · Physics 2019-08-07 Motohiko Ezawa

Bulk-boundary correspondence, connecting the bulk topology and the edge states, is an essential principle of the topological phases. However, the bulk-boundary correspondence is broken down in general non-Hermitian systems. In this paper,…

Mesoscale and Nanoscale Physics · Physics 2021-02-24 Yang Cao , Yang Li , Xiaosen Yang

In two dimensions, Hermitian lattices with non-zero Chern numbers and non-Hermitian lattices with a higher-order skin effect (HOSE) bypass the constraints of the Nielsen-Ninomiya no-go theorem at their one-dimensional boundaries. This…

Mesoscale and Nanoscale Physics · Physics 2025-05-22 Yifan Wang , Wladimir A. Benalcazar

Topological semimetals exhibit protected band crossings in momentum space, accompanied by corresponding surface states. Non-Hermitian Hamiltonians introduce geometry-sensitive features that dissolve this bulk-boundary correspondence…

Mesoscale and Nanoscale Physics · Physics 2025-06-18 Megan Schoenzeit , Chang Shu , Kai Zhang , Kai Sun

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

The topological band theory predicts that bulk materials with nontrivial topological phases support topological edge states. This phenomenon is universal for various wave systems and has been widely observed for electromagnetic and acoustic…

Mesoscale and Nanoscale Physics · Physics 2021-07-14 Hao Hu , Song Han , Yihao Yang , Dongjue Liu , Haoran Xue , Gui-Geng Liu , Zheyu Cheng , Qi Jie Wang , Shuang Zhang , Baile Zhang , Yu Luo

We consider a class of one-dimensional non-Hermitian models with a special type of a chiral symmetry which is related to pseudo-Hermiticity. We show that the topology of a Hamiltonian belonging to this symmetry class is determined by a…

Strongly Correlated Electrons · Physics 2019-10-16 Wojciech Brzezicki , Timo Hyart

The interplay of topology and non-Hermiticity has led to diverse, exciting manifestations in a plethora of systems. In this work, we systematically investigate the role of non-Hermiticity in the Chern insulating Haldane model on a dice…

Quantum Physics · Physics 2023-04-05 Ronika Sarkar , Arka Bandyopadhyay , Awadhesh Narayan

Topological phases feature robust edge states that are protected against the effects of defects and disorder. The robustness of these states presents opportunities to design technologies that are tolerant to fabrication errors and resilient…

A modified periodic boundary condition adequate for non-hermitian topological systems is proposed. Under this boundary condition a topological number characterizing the system is defined in the same way as in the corresponding hermitian…

Mesoscale and Nanoscale Physics · Physics 2019-11-04 Ken-Ichiro Imura , Yositake Takane

The bulk-edge correspondence is a fundamental principle of topological wave physics, which states that the difference in gap Chern numbers between the interfaced materials is equal to the net number of topological edge modes. Although this…

Optics · Physics 2022-02-09 Samaneh Pakniyat , S. Ali Hassani Gangaraj , George W Hanson

Recently, topological quantum states of non-Hermitian systems, exhibiting rich new exotic states, have attracted great attention in condensed-matter physics. As for the demonstration, most of non-Hermitian topological phenomena previously…

Mesoscale and Nanoscale Physics · Physics 2019-02-15 Huaiqiang Wang , Jiawei Ruan , Haijun Zhang

We show that the bulk-boundary correspondence for topological insulators can be modified in the presence of non-Hermiticity. We consider a one-dimensional tight-binding model with gain and loss as well as long-range hopping. The system is…

Quantum Physics · Physics 2016-04-04 Tony E. Lee

Topologically protected edge states exactly at topological phase boundaries challenge the conventional belief that topological states must be associated with a bulk energy gap. Because periodically driven (Floquet) systems host unusually…

Statistical Mechanics · Physics 2025-05-26 Longwen Zhou , Jiangbin Gong , Xue-Jia Yu

We study a non-Hermitian Rice-Mele model without breaking time-reversal symmetry, with the non-Hermiticity arising from imbalanced hopping rates. The Berry connection, Berry curvature and Chern number are introduced in the context of…

Quantum Physics · Physics 2018-10-24 R. Wang , X. Z. Zhang , Z. Song

Quantum dots are one of the paradigmatic solid-state systems for quantum engineering, providing an outstanding tunability to explore fundamental quantum phenomena. Here we show that non-Hermitian many-body topological modes can be realized…

Mesoscale and Nanoscale Physics · Physics 2022-02-07 Timo Hyart , Jose L. Lado

In Hermitian systems, according to the bulk-edge correspondence interfacing two topological optical media with different bulk topological numbers implies the existence of edge states, which can trap light at the interface. However, such a…

Optics · Physics 2021-12-21 Stefano Longhi

Non-Hermitian Hamiltonians, which describe a wide range of dissipative systems, and higher-order topological phases, which exhibit novel boundary states on corners and hinges, comprise two areas of intense current research. Here we…

Mesoscale and Nanoscale Physics · Physics 2019-03-13 Elisabet Edvardsson , Flore K. Kunst , Emil J. Bergholtz

Spectra of bulk or edges in topological insulators are often made complex by non-Hermiticity. Here, we show that symmetry protection enables entirely real spectra for both bulk and edges even in non-Hermitian topological insulators. In…

Mesoscale and Nanoscale Physics · Physics 2020-09-11 Kohei Kawabata , Masatoshi Sato