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Related papers: Non-Hermitian Dirac Cones

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Dirac points (DP) in Hermitian systems play a key role in topological phenomena. Their existence in non-Hermitian systems is then desirable, but the addition of loss or gain transforms DPs into pairs of Exceptional Points (EPs) joined by a…

Optics · Physics 2024-04-10 Pilar Pujol-Closa , Lluis Torner , David Artigas

We describe a diagrammatic technique for non-Hermitian fermionic systems that is applicable in the steady state, and which allows addressing correlations effects by systematic expansion. Applying this method to exceptional points or rings,…

Mesoscale and Nanoscale Physics · Physics 2020-01-29 Johan Carlström

Higher-order topology in non-Hermitian (NH) systems has recently become one of the most promising and rapidly developing fields in condensed matter physics. Many distinct phases that were not present in the Hermitian equivalents are shown…

Mesoscale and Nanoscale Physics · Physics 2023-05-17 Subhajyoti Bid , Gaurab Kumar Dash , Manisha Thakurathi

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

Recently, many novel and exotic phases have been proposed by considering the role of topology in non-Hermitian systems, and their emergent properties are of wide current interest. In this work we propose the non-Hermitian generalization of…

Mesoscale and Nanoscale Physics · Physics 2021-10-12 Ayan Banerjee , Awadhesh Narayan

We present the observation of diabolic points in Hermitian and non-Hermitian electronics dimers. The condition of unbreakable Parity-time symmetry is established for both PT-symmetric ZRC and RLC dimers. We show how appears non-Hermitian…

Applied Physics · Physics 2020-05-25 Stéphane Boris Tabeu , Fernande Fotsa-Ngaffo , Aurélien Kenfack-Jiotsa

Exceptional points, the spectral degeneracy points in the complex parameter space, are fundamental to non-Hermitian quantum systems. The dynamics of non-Hermitian systems in the presence of exceptional points differ significantly from those…

Quantum Physics · Physics 2021-01-29 Chon-Fai Kam , Yang Chen

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

We propose and show that application of light leads to an intriguing platform for controlling exceptional points in non-Hermitian topological systems. We demonstrate our proposal using three different non-Hermitian systems -- nodal line…

Mesoscale and Nanoscale Physics · Physics 2020-12-02 Ayan Banerjee , Awadhesh Narayan

We introduce feedback-measurement technologies to achieve flexible control of Weyl points and conduct the first experimental demonstration of Weyl type I-II transition in mechanical systems. We demonstrate that non-Hermiticity can expand…

Mesoscale and Nanoscale Physics · Physics 2024-03-25 Mingsheng Tian , Ivan Velkovsky , Tao Chen , Fengxiao Sun , Qiongyi He , Bryce Gadway

We show that a non-Hermitian lattice with a disclination can host topological disclination states that are induced by on-site gain and loss. The disclination states are inherently non-Hermitian as they do not exist in the limit of zero…

Mesoscale and Nanoscale Physics · Physics 2024-06-06 Rimi Banerjee , Subhaskar Mandal , Yun Yong Terh , Shuxin Lin , Gui-Geng Liu , Baile Zhang , Y. D. Chong

Recently, a Dirac exceptional point (EP) was reported in a non-Hermitian system. Unlike a Dirac point in Hermitian systems, this Dirac EP has coalesced eigenstates in addition to the degenerate energy. Also different from a typical EP, the…

Quantum Physics · Physics 2023-03-17 Jose H. D. Rivero , Liang Feng , Li Ge

Ultracold Fermi gases trapped in honeycomb optical lattices provide an intriguing scenario, where relativistic quantum electrodynamics can be tested. Here, we generalize this system to non-Abelian quantum electrodynamics, where massless…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 A. Bermudez , N. Goldman , A. Kubasiak , M. Lewenstein , M. A. Martin-Delgado

Parity-time ($\mathcal{PT}$) symmetry plays an important role both in non-Hermitian and topological systems. In non-Hermitian systems $\mathcal{PT}$ symmetry can lead to an entirely real energy spectrum, while in topological systems…

Mesoscale and Nanoscale Physics · Physics 2019-12-18 W. B. Rui , Moritz M. Hirschmann , Andreas P. Schnyder

Topological physics has broadened its scope from the study of topological insulating phases to include nodal phases containing band structure singularities. The geometry of the corresponding quantum states is described by the quantum metric…

Relativistic quasiparticles emerging from band degeneracies in crystals play crucial roles in the transport and topological properties of materials and metamaterials. Quasiparticles are commonly described by Hermitian Hamiltonians, with…

Mesoscale and Nanoscale Physics · Physics 2025-02-18 Xinrong Xie , Fei Ma , W. B. Rui , Zhaozhen Dong , Yulin Du , Wentao Xie , Y. X. Zhao , Hongsheng Chen , Fei Gao , Haoran Xue

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

Topological phases are greatly enriched by including non-Hermiticity. While most works focus on the topology of the eigenvalues and eigenstates, how topologically nontrivial non-Hermitian systems behave in dynamics has only drawn limited…

Mesoscale and Nanoscale Physics · Physics 2023-08-16 Tian-Rui Liu , Kai Bai , Jia-Zheng Li , Liang Fang , Duanduan Wan , Meng Xiao

Dirac materials have unique transport properties, partly due to the presence of surface states. A new type of Dirac materials, protected by non-symmorphic symmetries was recently proposed by Young and Kane [1]. By breaking of time reversal…

Mesoscale and Nanoscale Physics · Physics 2019-02-13 P. G. Matveeva , D. N. Aristov , D. Meidan , D. B. Gutman

We provide a systematic study of non-Hermitian topologically charged systems. Starting from a Hermitian Hamiltonian supporting Weyl points with arbitrary topological charge, adding a non-Hermitian perturbation transforms the Weyl points to…

Mesoscale and Nanoscale Physics · Physics 2018-02-21 Alexander Cerjan , Meng Xiao , Luqi Yuan , Shanhui Fan
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