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Related papers: Non-Hermitian Hopf insulators

200 papers

In this work, we present a collection of three-dimensional higher-order symmetry protected topological phases (HOSPTs) with gapless hinge modes that exist only in strongly interacting systems subject to subsystem symmetry constraints. We…

Strongly Correlated Electrons · Physics 2022-06-29 Julian May-Mann , Yizhi You , Taylor L. Hughes , Zhen Bi

The complex energy bands of non-Hermitian systems braid in momentum space even in one dimension. Here, we reveal that the non-Hermitian braiding underlies the Hermitian topological physics with chiral symmetry under a general framework that…

Mesoscale and Nanoscale Physics · Physics 2023-10-09 W. B. Rui , Y. X. Zhao , Z. D. Wang

We introduce the exceptional topological insulator (ETI), a non-Hermitian topological state of matter that features exotic non-Hermitian surface states which can only exist within the three-dimensional topological bulk embedding. We show…

Mesoscale and Nanoscale Physics · Physics 2021-10-04 M. Michael Denner , Anastasiia Skurativska , Frank Schindler , Mark H. Fischer , Ronny Thomale , Tomáš Bzdušek , Titus Neupert

The classification of point gap topology in all local non-Hermitian symmetry classes has been recently established. However, many entries in the resulting periodic table have only been discussed in a formal setting and still lack a physical…

Mesoscale and Nanoscale Physics · Physics 2023-09-04 M. Michael Denner , Titus Neupert , Frank Schindler

The notion of a band gap is ubiquitous in the characterization of matter. Particularly interesting are pseudo-gaps, which are enigmatic regions of very low density of states that have been linked to novel phenomena like high temperature…

Mesoscale and Nanoscale Physics · Physics 2022-03-10 Linhu Li , Ching Hua Lee

Self-propulsion is a quintessential aspect of biological systems, which can induce nonequilibrium phenomena that have no counterparts in passive systems. Motivated by biophysical interest together with recent advances in experimental…

Soft Condensed Matter · Physics 2026-02-26 Kazuki Sone , Kazuki Yokomizo , Kyogo Kawaguchi , Yuto Ashida

Non-Hermiticity can vary the topology of system, induce topological phase transition, and even invalidate the conventional bulk-boundary correspondence. Here, we show the introducing of non-Hermiticity without affecting the topological…

Mesoscale and Nanoscale Physics · Physics 2019-07-30 K. L. Zhang , H. C. Wu , L. Jin , Z. Song

Three-dimensional topological semimetals exhibit linear energy band crossing points that act as monopoles of Berry curvature. Here, an alternative class of semimetals is introduced, featuring linear $N$-fold crossing points each of which…

Mesoscale and Nanoscale Physics · Physics 2023-09-12 Ansgar Graf , Frédéric Piéchon

We present a quantitative, near-term experimental blueprint for the quantum simulation of topological insulators using lattice-trapped ultracold polar molecules. In particular, we focus on the so-called Hopf insulator, which represents a…

The non-Hermitian skin effect, as a unique feature of non-Hermitian systems, will break the topological energy braiding of the Bloch bands in open boundary systems. Going beyond the Bloch band theory, we unveil the energy braiding of the…

Mesoscale and Nanoscale Physics · Physics 2023-10-20 Yang Li , Xiang Ji , Yuanping Chen , Xiaohong Yan , Xiaosen Yang

While topology can impose obstructions to exponentially localized Wannier functions, certain topological insulators are exempt from such Wannier obstructions. The absence of the Wannier obstructions can further accompany topological…

Mesoscale and Nanoscale Physics · Physics 2025-08-29 Daichi Nakamura , Ken Shiozaki , Kenji Shimomura , Masatoshi Sato , Kohei Kawabata

We study the generalization of the three-dimensional two-band Hopf insulator to the case of many bands, where all the bands are separated from each other by band gaps. The obtained $\mathbb{Z}$ classification of such a $N$-band Hopf…

Mesoscale and Nanoscale Physics · Physics 2021-07-21 Bastien Lapierre , Titus Neupert , Luka Trifunovic

The multipartite non-Hermitian Su-Schrieffer-Heeger model is explored as a prototypical example of one-dimensional systems with several sublattice sites for unveiling intriguing insulating and metallic phases with no Hermitian counterparts.…

Mesoscale and Nanoscale Physics · Physics 2022-05-10 Ritu Nehra , Dibyendu Roy

Breaking Hermiticity in topological systems gives rise to intriguing phenomena, such as the exceptional topology and the non-Hermitian skin effect. In this work, we study a non-Hermitian topological crystalline insulator sitting on the…

Mesoscale and Nanoscale Physics · Physics 2022-02-11 Qiu-Yue Xu , Feng Liu , Chui-Zhen Chen , Dong-Hui Xu

Recent works have proved the existence of symmetry-protected edge states in certain one-dimensional topological band insulators and superconductors at the gap-closing points which define quantum phase transitions between two topologically…

Mesoscale and Nanoscale Physics · Physics 2021-10-20 Oleksandr Balabanov , Daniel Erkensten , Henrik Johannesson

We present a unified framework to systematically embed complex knotted and linked structures, beyond the torus family, into diverse topological phases, including Hopf insulators, classical spin liquids, topological semimetals, and…

Strongly Correlated Electrons · Physics 2025-03-27 Snigdh Sabharwal

Topological insulators are new quantum states with helical gapless edge or surface states inside the bulk band gap.These topological surface states are robust against the weak time-reversal invariant perturbations, such as lattice…

Mesoscale and Nanoscale Physics · Physics 2013-08-07 Haijun Zhang , Shou-Cheng Zhang

We propose a geometric criterion of the topological phase transition for non-Hermitian systems. We define the length of the boundary of the bulk band in the complex energy plane for non-Hermitian systems. For one-dimensional systems, we…

Quantum Physics · Physics 2023-08-14 Annan Fan , Shi-Dong Liang

Topological insulators are new states of quantum matter which can not be adiabatically connected to conventional insulators and semiconductors. They are characterized by a full insulating gap in the bulk and gapless edge or surface states…

Mesoscale and Nanoscale Physics · Physics 2011-11-09 Xiao-Liang Qi , Shou-Cheng Zhang

A non-Hermitian topological insulator with real spectrum is interesting in the theory of non-Hermitian extension of topological systems. We find an experimentally realizable example of a two dimensional non-Hermitian topological insulator…

Mesoscale and Nanoscale Physics · Physics 2019-10-16 C. Yuce , H. Ramezani