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Related papers: Non-Hermitian Chern bands

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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

A unique feature of non-Hermitian (NH) systems is the NH skin effect, i.e. the edge localization of an extensive number of bulk-band eigenstates in a lattice with open or semi-infinite boundaries. Unlike extended Bloch waves in Hermitian…

Quantum Physics · Physics 2022-04-14 Stefano Longhi

The traditional bulk-boundary correspondence assuring robust gapless modes at the edges and surfaces of insulating and nodal topological materials gets masked in non-Hermitian (NH) systems by the skin effect, manifesting an accumulation of…

Mesoscale and Nanoscale Physics · Physics 2022-07-14 Archisman Panigrahi , Roderich Moessner , Bitan Roy

The non-Bloch topology leads to the emergence of various counter-intuitive phenomena in non-Hermitian systems under the open boundary condition (OBC), which can not find a counterpart in Hermitian systems. However, in the non-Hermitian…

Quantum Physics · Physics 2024-07-29 Yue Zhang , Shuai Li , Yingchao Xu , Rui Tian , Miao Zhang , Hongrong Li , Hong Gao , M. Suhail Zubairy , Fuli Li , Bo Liu

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

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

The energy bands of non-Hermitian systems exhibit nontrivial topological features that arise from the complex nature of the energy spectrum. Under periodic boundary conditions (PBC), the energy spectrum describes rather generally closed…

Quantum Physics · Physics 2022-07-26 Stefano Longhi

A non-Hermitian topological insulator is fundamentally different from conventional topological insulators. The non-Hermitian skin effect arises in a nonreciprocal tight binding lattice with open edges. In this case, not only topological…

Mesoscale and Nanoscale Physics · Physics 2020-01-01 C. Yuce

In 2D Chern insulators (2D CI), the topology of the bulk states is captured by a topological invariant, the Chern number. The scalar bulk-boundary correspondence (sBBC) relates the change in Chern number across an interface with the number…

The bulk-boundary correspondence is an integral feature of topological analysis and the existence of boundary or interface modes offers direct insight into the topological structure of the Bloch wave function. While only the topology of the…

Strongly Correlated Electrons · Physics 2022-11-28 Chang-geun Oh , Doohee Cho , Se Young Park , Jun-Won Rhim

The bulk-edge correspondence (BEC) is the hallmark of topological systems. In continuous (nonlattice) Hermitian systems with an unbounded wave vector, it was recently shown that the BEC of Chern insulators is modified. How would it be…

Mesoscale and Nanoscale Physics · Physics 2023-02-13 Orr Rapoport , Moshe Goldstein

Non-Hermiticity naturally breaks down the adiabaticity and thus leads to non-Abelian behaviors in multi-band systems. Here, we study how non-Abelian properties emerge in non-Hermitian systems by considering a multi-band non-Hermitian model…

Mesoscale and Nanoscale Physics · Physics 2025-09-17 Ziyu Zhou , Zhi-Cong Xu , Li-Jun Lang

We consider conditions for the existence of boundary modes in non-Hermitian systems with edges of arbitrary co-dimension. Through a universal formulation of formation criteria for boundary modes in terms of local Green functions, we outline…

Mesoscale and Nanoscale Physics · Physics 2020-02-12 Dan S. Borgnia , Alex Jura Kruchkov , Robert-Jan Slager

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

Non-Hermitian band theory distinguishes between line gaps and point gaps. While point gaps can give rise to intrinsic non-Hermitian band topology without Hermitian counterparts, line-gapped systems can always be adiabatically deformed to a…

Mesoscale and Nanoscale Physics · Physics 2023-08-03 Frank Schindler , Kaiyuan Gu , Biao Lian , Kohei Kawabata

The interplay between non-Hermitian effects and topological insulators has become a frontier of research in non-Hermitian physics. However, the existence of a non-Hermitian skin effect for topological-protected edge states remains…

Quantum Physics · Physics 2024-05-29 Xinran Ma , Kui Cao , Xiaoran Wang , Zheng Wei , Supeng Kou

We show that anomalous Floquet topological insulators generate intrinsic, non-Hermitian topology on their boundary. As a consequence, removing a boundary hopping from the time-evolution operator stops the propagation of chiral edge modes,…

Mesoscale and Nanoscale Physics · Physics 2024-09-26 Hui Liu , Ion Cosma Fulga

Although the non-Bloch band theory is a milestone in elaborating bulk energy bands of non-Hermitian systems under the open-boundary condition (OBC), vital issues related to multivalued functions of non-Hermitian energy bands remain…

Mesoscale and Nanoscale Physics · Physics 2023-03-15 Yongxu Fu , Yi Zhang

There has been much recent interest and progress on topological structures of the non-Hermitian Bloch bands. Here, we study the topological structures of non-Bloch bands of non-Hermitian multiband quantum systems under open boundary…

Mesoscale and Nanoscale Physics · Physics 2024-09-10 Yongxu Fu , Yi Zhang

Two-band model works well for Hall effect in topological insulators. It turns out to be non-Hermitian when the system is subjected to environments, and its topology characterized by Chern numbers has received extensive studies in the past…

Mesoscale and Nanoscale Physics · Physics 2021-04-05 Junjie Wang , Fude Li , X. X. Yi