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Related papers: Non-Hermitian Higher-Order Dirac Semimetals

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We study a new class of non-Hermitian topological phases in three dimension in the absence of any symmetry, where the topological robust band degeneracies are Hopf-link exceptional lines. As a concrete example, we investigate the…

Mesoscale and Nanoscale Physics · Physics 2019-12-17 Zhesen Yang , Jiangping Hu

We give a bulk-hinge correspondence for higher-order topological phases protected by rotoinversion $C_{4}\mathcal{I}$ symmetry in magnetic systems. Our approach allows us to show the emergence of the chiral hinge modes only from the…

Mesoscale and Nanoscale Physics · Physics 2022-03-16 Yutaro Tanaka , Ryo Takahashi , Ryo Okugawa , Shuichi Murakami

Semimetals, in which conduction and valence bands touch but do not form Fermi surfaces, have attracted considerable interest for their anomalous properties starting with the discovery of Dirac matter in graphene and other two-dimensional…

Strongly Correlated Electrons · Physics 2018-09-11 Dennis Wawrzik , David Lindner , Maria Hermanns , Simon Trebst

Three-dimensional Dirac semimetals (DSMs) have been shown to exhibit one-dimensional hinge modes which are termed the higher-order hinge Fermi-arc (HOFA) states. They are the topological consequences of Dirac points. Superconducting states…

Superconductivity · Physics 2024-12-11 Guan-Hao Feng

The past decades have witnessed the flourishing of non-Hermitian physics in non-conservative systems, leading to unprecedented phenomena of unidirectional invisibility, enhanced sensitivity and more recently the novel topological features…

Mesoscale and Nanoscale Physics · Physics 2022-05-18 Xiujuan Zhang , Tian Zhang , Ming-Hui Lu , Yan-Feng Chen

Topological phases of matter are conventionally characterized by the bulk-boundary correspondence in Hermitian systems: The topological invariant of the bulk in $d$ dimensions corresponds to the number of $(d-1)$-dimensional boundary…

In recent years, there has been a surge of interest in exploring higher-order topology and their semi-metallic counterparts, particularly in the context of Dirac, Weyl, and nodal line semimetals, termed as higher-order Dirac semimetal…

Mesoscale and Nanoscale Physics · Physics 2025-05-29 Amartya Pal , Arnob Kumar Ghosh

Recently, there has been a lot of activity in the research field of topological non-Hermitian physics, partly driven by fundamental interests and partly driven by applications in photonics. However, despite these activities, a general…

Mesoscale and Nanoscale Physics · Physics 2019-06-26 W. B. Rui , Y. X. Zhao , Andreas P. Schnyder

Non-Hermitian physics has added new ingredients to topological physics, leading to the rising frontier of non-Hermitian topological phases. In this study, we investigate Chern insulator phases emerging from non-Hermitian kagome models with…

Materials Science · Physics 2024-05-13 Li-Wei Wang , Zhi-Kang Lin , Jian-Hua Jiang

Topological edge modes are excitations that are localized at the materials' edges and yet are characterized by a topological invariant defined in the bulk. Such bulk-edge correspondence has enabled the creation of robust electronic,…

Mesoscale and Nanoscale Physics · Physics 2020-11-30 Ananya Ghatak , Martin Brandenbourger , Jasper van Wezel , Corentin Coulais

The current understanding of the role of topology in non-Hermitian (NH) systems and its far-reaching physical consequences observable in a range of dissipative settings are reviewed. In particular, how the paramount and genuinely NH concept…

Mesoscale and Nanoscale Physics · Physics 2021-03-03 Emil J. Bergholtz , Jan Carl Budich , Flore K. Kunst

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

We report on the occurrence of knotted metallic band structures as stable topological phases in non-Hermitian (NH) systems. These knotted NH metals are characterized by open Fermi surfaces, known in mathematics as Seifert surfaces, that are…

Mesoscale and Nanoscale Physics · Physics 2019-05-01 Johan Carlström , Marcus Stålhammar , Jan Carl Budich , Emil J. Bergholtz

The bulk Fermi arc is a fundamental non-Hermitian topological feature that connects two exceptional points (EPs), featuring the transition between Hermitian and non-Hermitian worlds. The bulk Fermi arc emerges when losses are introduced…

We investigate novel features of three dimensional non-Hermitian Weyl semimetals, paying special attention to its unconventional bulk-boundary correspondence. We use the non-Bloch Chern numbers as the tool to obtain the topological phase…

Mesoscale and Nanoscale Physics · Physics 2019-04-05 Xiaosen Yang , Yang Cao , Yunjia Zhai

We establish non-Hermitian topological mechanics in one dimensional (1D) and two dimensional (2D) lattices consisting of mass points connected by meta-beams that lead to odd elasticity. Extended from the "non-Hermitian skin effect" in 1D…

Soft Condensed Matter · Physics 2020-05-19 Di Zhou , Junyi Zhang

In the presence of certain symmetries, three-dimensional Dirac semimetals can harbor not only surface Fermi arcs, but also surface Dirac cones. Motivated by the experimental observation of rotation-symmetry-protected Dirac semimetal states…

Superconductivity · Physics 2022-01-17 Majid Kheirkhah , Zheng-Yang Zhuang , Joseph Maciejko , Zhongbo Yan

Non-Hermitian (NH) Dirac semimetals describe open gain--loss systems. Yet at charge neutrality, models featuring real spectrum often look Hermitian-like, with NH effects absorbed into renormalized band parameters. Here, we show that a…

Mesoscale and Nanoscale Physics · Physics 2026-05-19 Sergio Pino-Alarcón , Juan Pablo Esparza , Vladimir Juričić

Non-Hermitian skin-edge states emerge only at one edge in one-dimensional nonreciprocal chains, where all states are localized at the edge irrespective of eigenvalues. The bulk topological number is the winding number associated with the…

Mesoscale and Nanoscale Physics · Physics 2019-05-10 Motohiko Ezawa

Non-Hermitian topological phases exhibit a number of exotic features that have no Hermitian counterparts, including the skin effect and breakdown of the conventional bulk-boundary correspondence. Here, we implement the non-Hermitian…