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Related papers: Exceptional Topological Insulators

200 papers

Owing to the presence of exceptional points (EPs), non-Hermitian (NH) systems can display intriguing topological phenomena without Hermitian analogs. However, experimental characterizations of exceptional topological invariants have been…

We report the discovery of several classes of novel topological insulators (TIs) with hybrid-order boundary states generated from the first-order TIs with additional crystalline symmetries. Unlike the current studies on hybrid-order TIs…

Mesoscale and Nanoscale Physics · Physics 2025-05-09 Yan-Qing Zhu , Zhen Zheng , Giandomenico Palumbo , Z. D. Wang

Quantum spin-hall insulator (QSHI) processes nontrivial topology. We notice that the electronic structures of some particular QSHIs are favorable for realization of excitonic insulators (EIs). Using first-principles many-body perturbation…

Materials Science · Physics 2023-04-04 Huaiyuan Yang , Jiaxi Zeng , Yuelin Shao , Yuanfeng Xu , Xi Dai , Xin-Zheng Li

Hopf insulators represent a unique class of topological insulators that exist exclusively in two-band systems and are inherently unstable upon the inclusion of additional bands. Meanwhile, recent studies have shown that non-Hermiticity…

Mesoscale and Nanoscale Physics · Physics 2025-08-20 Daichi Nakamura , Kohei Kawabata

Non-Hermitian systems can exhibit unique topological and localization properties. Here we elucidate the non-Hermitian effects on disordered topological systems by studying a non-Hermitian disordered Su-Schrieffer-Heeger model with…

Quantum Physics · Physics 2020-04-15 Dan-Wei Zhang , Ling-Zhi Tang , Li-Jun Lang , Hui Yan , Shi-Liang Zhu

The discovery of topological phases in non-Hermitian open classical and quantum systems challenges our current understanding of topological order. Non-Hermitian systems exhibit unique features with no counterparts in topological Hermitian…

Mesoscale and Nanoscale Physics · Physics 2019-06-26 Stefano Longhi

Topological edge states appear at the interface of topologically distinct two Hermitian insulators. We study the extension of this idea to non-Hermitian systems. We consider PT symmetric and topologically distinct non-Hermitian insulators…

Mesoscale and Nanoscale Physics · Physics 2019-05-21 C. Yuce

We reveal how symmetry protected nodal points in topological semimetals may be promoted to pairs of generically stable exceptional points (EPs) by symmetry-breaking fluctuations at the onset of long-range order. This novel route to…

Strongly Correlated Electrons · Physics 2023-10-09 Lorenzo Crippa , Giorgio Sangiovanni , Jan Carl Budich

This paper reports on the experimental observation of topologically protected edge state and exceptional point in an open and Non-Hermitian system. While the theoretical underpinning is generic to wave physics, the simulations and…

Mesoscale and Nanoscale Physics · Physics 2018-09-26 Weiwei Zhu , Xinsheng Fang , Dongting Li , Yong Sun , Yong Li , Yun Jing , Hong Chen

It is well known that the 3D electronic topological insulator (TI) with charge-conservation and time-reversal symmetry cannot have a trivial insulating surface that preserves symmetry. It is often implicitly assumed that if the TI surface…

Strongly Correlated Electrons · Physics 2014-05-20 Chong Wang , Andrew C. Potter , T. Senthil

Non-Hermitian theory is a theoretical framework that excels at describing open systems. It offers a powerful tool in the characterization of both the intrinsic degrees of freedom (DOFs) of a system and the interactions with the external…

Quantum Physics · Physics 2024-05-28 Kun Ding , Chen Fang , Guancong Ma

Topological insulators are electronic materials that have a bulk band gap like an ordinary insulator, but have protected conducting states on their edge or surface. The 2D topological insulator is a quantum spin Hall insulator, which is a…

Mesoscale and Nanoscale Physics · Physics 2015-03-13 M. Z. Hasan , C. L. Kane

Non-Hermitian systems can host topological states with novel topological invariants and bulk-edge correspondences that are distinct from conventional Hermitian systems. Here we show that two unique classes of non-Hermitian 2D topological…

Mesoscale and Nanoscale Physics · Physics 2021-03-10 Junpeng Hou , Ya-Jie Wu , Chuanwei Zhang

We propose a novel way of modulating exceptional topology by implementing Floquet engineering in non-hermitian (NH) systems. We introduce Floquet exceptional topological insulator which results from shining light on a conventional…

Mesoscale and Nanoscale Physics · Physics 2024-02-23 Gaurab Kumar Dash , Subhajyoti Bid , Manisha Thakurathi

Exceptional point (EP) is a spectral singularity in non-Hermitian systems. The passing over the EP leads to a phase transition, which endows the system with unconventional features that find a wide range of applications. However, the need…

Quantum Physics · Physics 2023-04-19 T. T. Sergeev , A. A. Zyablovsky , E. S. Andrianov , Yu. E. Lozovik

We provide classification of gapless phases in non-Hermitian systems according to two types of complex-energy gaps: point gap and line gap. We show that exceptional points, at which not only eigenenergies but also eigenstates coalesce, are…

Mesoscale and Nanoscale Physics · Physics 2020-04-22 Takumi Bessho , Kohei Kawabata , Masatoshi Sato

Eigenenergies of a non-Hermitian system without parity-time symmetry are complex in general. Here, we show that the chiral boundary states of higher-dimensional (two-dimensional and three-dimensional) non-Hermitian topological insulators…

Mesoscale and Nanoscale Physics · Physics 2022-03-14 C. Wang , X. R. Wang

The concept of topological insulator (TI) has introduced a new point of view to condensed-matter physics, relating a priori unrelated subfields such as quantum (spin, anomalous) Hall effects, spin-orbit coupled materials, some classes of…

Mesoscale and Nanoscale Physics · Physics 2015-01-20 Yukinori Yoshimura , Koji Kobayashi , Tomi Ohtsuki , Ken-Ichiro Imura

Topological insulators are a new class of insulators in which a bulk gap for electronic excitations is generated by strong spin orbit coupling. These novel materials are distinguished from ordinary insulators by the presence of gapless…

It was known that for non-Hermitian topological systems due to the non-Hermitian skin effect, the bulk-edge correspondence is broken down. In this paper, by using one-dimensional Su-SchriefferHeeger model and two-dimensional (deformed)…

Mesoscale and Nanoscale Physics · Physics 2020-05-20 Can Wang , Xiao-Ran Wang , Cui-Xian Guo , Su-Peng Kou