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Related papers: Non-Bloch bands in two-dimensional non-Hermitian s…

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In two-dimensional anomalous Floquet insulators, non-Hermitian boundary state engineering can be used to completely separate chiral boundary states from bulk bands in the quasienergy spectrum. The topological properties of such spectrally…

Mesoscale and Nanoscale Physics · Physics 2020-09-07 Bastian Höckendorf , Andreas Alvermann , Holger Fehske

The Hopf insulator is a three-dimensional topological insulator outside the standard classification of topological insulators. Here we consider two types of non-Hermitian Hopf insulators, one without and one with the non-Hermitian skin…

Mesoscale and Nanoscale Physics · Physics 2020-07-08 Yan He , Chih-Chun Chien

Non-Hermiticity gives rise to distinctive topological phenomena absent in Hermitian systems. However, connection between such intrinsic non-Hermitian topology and Hermitian topology has remained largely elusive. Here, considering the bulk…

Mesoscale and Nanoscale Physics · Physics 2025-01-07 Shu Hamanaka , Tsuneya Yoshida , Kohei Kawabata

Topology plays a central role in nearly all disciplines of physics, yet its applications have so far been restricted to closed, lossless systems in thermodynamic equilibrium. Given that many physical systems are open and may include gain…

Mesoscale and Nanoscale Physics · Physics 2019-08-21 Mark R. Hirsbrunner , Timothy M. Philip , Matthew J. Gilbert

The non-Hermitian skin effect (NHSE) is a hallmark of non-Hermitian system, yet its generalized Brillouin zone (GBZ) description is restricted to periodic systems. We develop a site-resolved theory via a local scaling transformation (LST),…

Mesoscale and Nanoscale Physics · Physics 2026-05-26 Chen-Hao Zhao , Jia-Rui Li , Yuping Tian , Wei-Jiang Gong

As one indispensable type of nonreciprocal mechanism, a system with temporal modulations is intrinsically open in the physical sense and inevitably non-Hermitian, but the space and time degrees of freedom are nonseparable in a large variety…

Optics · Physics 2024-08-14 Haozhi Ding , Kun Ding

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

Non-Hermitian topological insulators have attracted considerable attention due to their distinctive energy band characteristics and promising applications. Here, we systematically investigate non-Hermitian M\"obius insulators and…

Mesoscale and Nanoscale Physics · Physics 2025-06-18 Wenjie Zhang , Yuting Yang , Xiaopeng Shen , Liwei Shi , Zhi Hong Hang

The effect of non-Hermiticity in band topology has sparked many discussions on non-Hermitian topological physics. It has long been known that non-Hermitian Hamiltonians can exhibit real energy spectra under the condition of parity-time…

Mesoscale and Nanoscale Physics · Physics 2024-03-20 Yang Long , Haoran Xue , Baile Zhang

In this letter we study the Hall conductance for a non-Hermitian Chern insulator and quantitatively describe how the Hall conductance deviates from a quantized value. We show the effects of the non-Hermitian terms on the Hall conductance…

Mesoscale and Nanoscale Physics · Physics 2018-12-26 Yu Chen , Hui Zhai

Periodically driven systems, characterised by their inherent non-equilibrium dynamics, are ubiquitously found in both classical and quantum regimes. In the field of photonics, these Floquet systems have begun to provide insight into how…

Topological states in non-Hermitian systems are known to exhibit some anomalous features. Here, we find two new anomalous features of non-Hermitian topological states. We consider a one dimensional nonreciprocal Hamiltonian and show that…

Mesoscale and Nanoscale Physics · Physics 2020-03-18 C. Yuce

Moir\'e flat bands in rhombohedral multilayer graphene provide a platform for exploring interaction-driven topological phases, where a single isolated band often forms a Chern band. However, non-Abelian degenerate Chern bands with internal…

Mesoscale and Nanoscale Physics · Physics 2026-04-16 Taketo Uchida , Takuto Kawakami , Mikito Koshino

For decades, the topological phenomena in quantum systems have always been catching our attention. Recently, there are many interests on the systems where topologically protected edge states exist, even in the presence of non-Hermiticity.…

Quantum Gases · Physics 2020-09-15 Shujie Cheng , Gao Xianlong

It is well known that a single Dirac cone at high-symmetry point (HSP) of a Brillouin zone, akin to the one in graphenes' band structure, can not appear as the only quasiparticle at the Fermi level in two-dimensional (2D), non-magnetic…

Mesoscale and Nanoscale Physics · Physics 2024-09-16 Vladimir Damljanovic

Non-Hermitian band topology can give rise to phenomena with no counterparts in Hermitian systems. A well-known example is the non-Hermitian skin effect (NHSE), where Bloch eigenstates localize at a boundary, induced by a nontrivial spectrum…

Mesoscale and Nanoscale Physics · Physics 2025-08-28 Hong-Yu Zou , Bing-Bing Wang , Yong Ge , Ke-Qi Zhao , Yu-Qi Chen , Hong-Xiang Sun , Shou-Qi Yuan , Haoran Xue , Baile Zhang

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 paper, we study the non-Hermitian system under dissipation and give the effective 2*2 Hamiltonian in the k-space by reducing the N*N Hamiltonian in the real space for them. It is discovered that the energy band shows an imaginary…

Mesoscale and Nanoscale Physics · Physics 2024-06-27 Qian Du , Xin-Ran Ma , Su-Peng Kou

We show that flat bands can be categorized into two distinct classes, that is, singular and nonsingular flat bands, by exploiting the singular behavior of their Bloch wave functions in momentum space. In the case of a singular flat band,…

Strongly Correlated Electrons · Physics 2019-01-09 Jun-Won Rhim , Bohm-Jung Yang

Parity-time (PT)-symmetric Hamiltonians have widespread significance in non-Hermitian physics. A PT-symmetric Hamiltonian can exhibit distinct phases with either real or complex eigenspectrum, while the transition points in between, the…

Quantum Physics · Physics 2021-07-13 Lei Xiao , Tianshu Deng , Kunkun Wang , Zhong Wang , Wei Yi , Peng Xue