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Related papers: Exceptional second-order topological insulators

200 papers

Compared with conventional topological insulator that carries topological state at its boundaries, the higher-order topological insulator exhibits lower-dimensional gapless boundary states at its corners and hinges. Leveraging the form…

Applied Physics · Physics 2024-04-25 Zhoufei Liu , Pei-Chao Cao , Liujun Xu , Guoqiang Xu , Ying Li , Jiping Huang

In this work we study many-body 'steady states' that arise in the non-Hermitian generalisation of the non-interacting Su-Schrieffer-Heeger model at a finite density of fermions. We find that the hitherto known phase diagrams for this…

Mesoscale and Nanoscale Physics · Physics 2022-05-17 Ayan Banerjee , Suraj S. Hegde , Adhip Agarwala , Awadhesh Narayan

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

In this work we explore experimental signatures of fractional topological insulators in three dimensions. These are states of matter with a fully gapped bulk that host exotic gapless surface states and fractionally charged quasiparticles.…

Strongly Correlated Electrons · Physics 2013-05-30 Brian Swingle

We propose a two-dimensional non-Hermitian Chern insulator with inversion symmetry, which is anisotropic and has staggered gain and loss in both x and y directions. In this system, conventional bulk-boundary correspondence holds. The Chern…

Mesoscale and Nanoscale Physics · Physics 2019-10-11 H. C. Wu , L. Jin , Z. Song

Eigenstate coalescence in non-Hermitian systems is widely observed in diverse scientific domains encompassing optics and open quantum systems. Recent investigations have revealed that adiabatic encircling of exceptional points (EPs) leads…

Quantum Physics · Physics 2023-06-13 Jung-Wan Ryu , Jae-Ho Han , Chang-Hwan Yi , Moon Jip Park , Hee Chul Park

Second-order photonic topological insulators that host highly localized corner states resilient to defects, are opening new routes towards developing fascinating photonic devices. However, the existing works on second-order photonic…

Optics · Physics 2021-12-02 Yafeng Chen , Fei Meng , Zhihao Lan , Baohua Jia , Xiaodong Huang

Recently, it has been found that there exist symmetry-protected topological phases of fermions, which have no realizations in non-interacting fermionic systems or bosonic models. We study the edge states of such an intrinsically interacting…

Strongly Correlated Electrons · Physics 2020-08-05 Joseph Sullivan , Meng Cheng

Searching for topological insulators/superconductors is a central subject in recent condensed matter physics. As a theoretical aspect, various classification methods of symmetry-protected topological phases have been developed, where the…

Superconductivity · Physics 2021-12-01 Shuntaro Sumita , Youichi Yanase

We classify topological phases of non-Hermitian systems in the Altland-Zirnbauer classes with an additional reflection symmetry in all dimensions. By mapping the non-Hermitian system into an enlarged Hermitian Hamiltonian with an enforced…

Mesoscale and Nanoscale Physics · Physics 2019-03-13 Chun-Hui Liu , Hui Jiang , Shu Chen

We show that the gapless boundary signatures - namely, chiral/helical hinge modes or localized zero modes - of three-dimensional higher-order topological insulators and superconductors with inversion symmetry can be gapped without symmetry…

Strongly Correlated Electrons · Physics 2022-09-27 Ming-Hao Li , Titus Neupert , S. A. Parameswaran , Apoorv Tiwari

Exceptional points are interesting physical phenomena in non-Hermitian physics at which the eigenvalues are degenerate and the eigenvectors coalesce. In this paper, we find that the universal feature of arbitrary non-Hermitian two level…

Quantum Physics · Physics 2022-01-25 X. R. Wang , F. Yang , X. J. Yu , X. Q. Tong , S. P. Kou

Exceptional points (EPs) are non-Hermitian degeneracies where eigenvalues and eigenvectors coalesce, giving rise to unusual physical effects across scientific disciplines. The concept of EPs has recently been extended to nonlinear physical…

The discovery and realization of topological insulators, a phase of matter which hosts metallic boundary states when the $d$-dimension insulating bulk is confined to ($d-1$)-dimensions, led to several potential applications. Recently, it…

We use low-depth quantum circuits, a specific type of tensor networks, to classify two-dimensional symmetry-protected topological many-body localized phases. For (anti-)unitary on-site symmetries we show that the (generalized) third…

Disordered Systems and Neural Networks · Physics 2020-07-29 Joey Li , Amos Chan , Thorsten B. Wahl

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…

Non-Hermiticity appears ubiquitously in various open classical and quantum systems and enriches classification of topological phases. However, the role of nonsymmorphic symmetry, crystalline symmetry accompanying fractional lattice…

Mesoscale and Nanoscale Physics · Physics 2025-04-30 Daichi Nakamura , Yutaro Tanaka , Ken Shiozaki , Kohei Kawabata

We consider symmetry protected topological (SPT) phases with crystalline point group symmetry, dubbed point group SPT (pgSPT) phases. We show that such phases can be understood in terms of lower-dimensional topological phases with on-site…

Strongly Correlated Electrons · Physics 2017-04-06 Hao Song , Sheng-Jie Huang , Liang Fu , Michael Hermele

We consider a non-Hermitian (NH) analog of a second-order topological insulator, protected by chiral symmetry, in the presence of next-nearest neighbor hopping elements to theoretically investigate the interplay beyond the first nearest…

Mesoscale and Nanoscale Physics · Physics 2024-09-16 Arnob Kumar Ghosh , Arijit Saha , Tanay Nag

In the presence of crystalline symmetries, second-order topological insulators can be featured by the polarization which is believed identical to the Wannier center. In this Letter, we show that second-order topological insulators are…

Optics · Physics 2022-08-22 Zhenzhen Liu , Guochao Wei , Jun-Jun Xiao