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Related papers: Corner modes in non-Hermitian next-nearest-neighbo…

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Genuinely non-Hermitian topological phases can be realized in open systems with sufficiently strong gain and loss; in such phases, the Hamiltonian cannot be deformed into a gapped Hermitian Hamiltonian without energy bands touching each…

Mesoscale and Nanoscale Physics · Physics 2021-06-02 Heinrich-Gregor Zirnstein , Gil Refael , Bernd Rosenow

The ease of using optical gain/loss provides a fertile ground for experimental explorations of non-Hermitian (NH) physics. Without gain/loss, can we realize the NH effect in a Hermitian system? The interface between the coupled Hermitian…

We theoretically investigate emergent topological phases in an extended spin-full Su-Schrieffer-Heeger (SSH) model considering Rashba spin-orbit interaction, all possible complex next to next nearest neighbor (NNNN) hopping preserving…

Mesoscale and Nanoscale Physics · Physics 2024-10-15 Hemant Kumar Sharma , Arijit Saha , Saptarshi Mandal

Non-Hermitian singularities are ubiquitous in non-conservative open systems. These singularities are often points of measure zero in the eigenspectrum of the system which make them difficult to access without careful engineering. Despite…

Quantum Physics · Physics 2018-05-24 Qi Zhong , Mercedeh Khajavikhan , Demetrios Christodoulides , Ramy El-Ganainy

We study the non-Hermitian Aubry-Andr\'e-Harper model, incorporating complex phase modulation, unmodulated and modulated nonreciprocal hopping. Using Avila's global theory, we derive analytical phase boundaries and map out the phase…

Disordered Systems and Neural Networks · Physics 2025-01-27 Xianqi Tong , Yiling Zhang , Bin Li , Xiaosen Yang

Higher-order topological phases (HOTPs) possess localized and symmetry-protected eigenmodes at corners and along hinges in two and three dimensional lattices. The numbers of these topological boundary modes will undergo quantized changes at…

Quantum Physics · Physics 2025-04-25 Longwen Zhou , Rongtao Wang , Jiaxin Pan

Symmetry and topology are essential principles in topological physics. Recently, the idea of sub-symmetry-protected topology -- where some of the original symmetries are broken while a remaining subset, called sub-symmetries, continues to…

Mesoscale and Nanoscale Physics · Physics 2026-01-09 Myungjun Kang , Wonjun Sung , Sonu Verma , Sangmo Cheon

Topological materials exhibit edge-localized scattering-free modes protected by their nontrivial bulk topology through the bulk-edge correspondence in Hermitian systems. While topological phenomena have recently been much investigated in…

Mesoscale and Nanoscale Physics · Physics 2020-11-16 Kazuki Sone , Yuto Ashida , Takahiro Sagawa

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

In this paper we study the effect of next-nearest-neighbor hopping on the dynamics of a single hole in an antiferromagnetic (N\'{e}el) background. In the framework of large dimensions the Green function of a hole can be obtained exactly.…

Condensed Matter · Physics 2009-10-22 Avraham Schiller , Pradeep Kumar , Rainer Strack , Dieter Vollhardt

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

We predict a re-entrant topological transition in a one dimensional non-Hermitian quasiperiodic lattice. By considering a non-Hermitian generalized Aubry-Andr\'e-Harper (AAH) model with quasiperiodic potential, we show that the system first…

Quantum Gases · Physics 2023-06-21 Ashirbad Padhan , Soumya Ranjan Padhi , Tapan Mishra

One of the hallmarks of bulk topology is the existence of robust boundary localized states. For instance, a conventional $d$ dimensional topological system hosts $d{-}1$ dimensional surface modes, which are protected by non-spatial…

Mesoscale and Nanoscale Physics · Physics 2021-05-11 Ruchira V Bhat , Soumya Bera

Exploring novel topological matters with exotic quantum states has always been a core issue in the field of condensed matter physics, which can update the understanding of topological phases and broaden the classification of topological…

Mesoscale and Nanoscale Physics · Physics 2025-12-09 Wei Jia , Yuping Tian , Huanhuan Yang , Xiangru Kong , Zhi-Hao Huang , Wei-Jiang Gong , Jun-Hong An

For two-dimensional lattices in a tight-binding description, the intrinsic spin-orbit coupling, acting as a complex next-nearest-neighbor hopping, opens gaps that exhibit the quantum spin Hall effect. In this paper, we study the effect of a…

Mesoscale and Nanoscale Physics · Physics 2020-05-28 W. Beugeling , J. C. Everts , C. Morais Smith

We investigate the appearance of mobility edges in a one-dimensional non-Hermitian tight-banding model with alternating hopping constants and slowly varying quasi-periodic on-site potentials. Due to the presence of slowly varying exponent,…

Disordered Systems and Neural Networks · Physics 2024-11-22 Qiyun Tang , Yan He

Starting from a double quantum dot realization of a minimal Kitaev chain, we demonstrate that non-Hermicity stabilizes the so-called poor man's Majorana zero modes in a region of parameter space that is much broader than in the Hermitian…

Mesoscale and Nanoscale Physics · Physics 2025-05-30 Jorge Cayao , Ramón Aguado

We investigate a non-Hermitian Aubry-Andr\'e-Harper model with short-range, as well as long-range p-wave pairing. Here, the non-Hermiticity is introduced through the onsite potential. A comprehensive analysis of several critical aspects of…

Disordered Systems and Neural Networks · Physics 2024-06-17 Shaina Gandhi , Jayendra N. Bandyopadhyay

We investigate gap-closings in one- and two-dimensional tight-binding models with two bands, containing non-Hermitian hopping terms, and open boundary conditions (OBCs) imposed along one direction. We compare the bulk OBC spectra with the…

Quantum Physics · Physics 2024-11-22 Ipsita Mandal

Solids built out of active components can exhibit non-reciprocal elastic coefficients that give rise to non-Hermitian wave phenomena. Here, we investigate non-Hermitian effects present at the boundary of two-dimensional active elastic media…

Soft Condensed Matter · Physics 2020-09-16 Colin Scheibner , William T. M. Irvine , Vincenzo Vitelli