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Related papers: Non-Bloch $\mathcal{PT}$ symmetry breaking in non-…

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The effects of gain and loss on the band structures of a bulk topological dielectric photonic crystal (PC) with $C_{6v}$ symmetry and the PC-air-PC interface are studied based on first-principle calculation. To illustrate the importance of…

Topological edge states arise in parity-time ($\mathcal{PT}$)-symmetric non-unitary quantum dynamics but have so far only been discussed in the $\mathcal{PT}$-symmetry-unbroken regime. Here we report the experimental detection of robust…

Quantum Physics · Physics 2019-06-19 Lei Xiao , Xingze Qiu , Kunkun Wang , Barry C. Sanders , Wei Yi , Peng Xue

The discovery of topological phases in non-Hermitian open classical and quantum systems challenges our current understanding of topological order. Non-Hermitian systems exhibit unique features with no counterparts in topological Hermitian…

Mesoscale and Nanoscale Physics · Physics 2019-06-26 Stefano Longhi

We identify and investigate two classes of non-Hermitian systems, i.e., one resulting from Lorentz-symmetry violation (LSV) and the other from a complex mass (CM) with Lorentz invariance, from the perspective of quantum field theory. The…

Mesoscale and Nanoscale Physics · Physics 2019-08-21 Zi-Yong Ge , Yu-Ran Zhang , Tao Liu , Si-Wen Li , Heng Fan , Franco Nori

The topology of non-Hermitian systems is drastically shaped by the non-Hermitian skin effect, which leads to the generalized bulk-boundary correspondence and non-Bloch band theory. The essential part in formulations of bulk-boundary…

Mesoscale and Nanoscale Physics · Physics 2019-12-11 Fei Song , Shunyu Yao , Zhong Wang

The bulk-boundary or bulk-edge correspondence is a principle relating surface confined states to the topological classification of the bulk. By combining non-Hermitian ingredients in terms of gain or loss with media that violate…

Mesoscale and Nanoscale Physics · Physics 2020-11-18 Penglin Gao , Morten Willatzen , Johan Christensen

Hermitian topological materials are characterized by the nontrivial relation between topological numbers and edge modes, i.e. the bulk-boundary correspondence. In non-Hermitian systems, the conventional correspondence breaks down. Instead,…

Strongly Correlated Electrons · Physics 2022-11-22 Shohei Masuda , Masaaki Nakamura

Non-Hermitian systems exhibit striking exceptions from the paradigmatic bulk-boundary correspondence, including the failure of bulk Bloch band invariants in predicting boundary states and the (dis)appearance of boundary states at parameter…

Mesoscale and Nanoscale Physics · Physics 2018-07-17 Flore K. Kunst , Elisabet Edvardsson , Jan Carl Budich , Emil J. Bergholtz

We construct a two-dimensional, discrete-time quantum walk exhibiting non-Hermitian skin effects under open-boundary conditions. As a confirmation of the non-Hermitian bulk-boundary correspondence, we show that the emergence of topological…

Mesoscale and Nanoscale Physics · Physics 2021-03-03 Tianyu Li , Yong-Sheng Zhang , Wei Yi

We demonstrate that the non-Hermitian parity-time (PT) symmetric interfaces formed between amplifying and lossy crystals support dissipationless edge states. These PT edge states exhibit gapless spectra in the complex band structure…

Mesoscale and Nanoscale Physics · Physics 2018-10-24 Xiang Ni , Daria Smirnova , Alexander Poddubny , Daniel Leykam , Yidong Chong , Alexander B. Khanikaev

Topological phases and the associated multiple edge states are studied for parity and time-reversal $(\mathcal{PT})$ symmetric non-Hermitian open quantum systems by constructing a non-unitary three-step quantum walk retaining $\mathcal{PT}$…

Quantum Physics · Physics 2020-09-14 Makio Kawasaki , Ken Mochizuki , Norio Kawakami , Hideaki Obuse

The high sensitivity of the spectrum and wavefunctions to boundary conditions, termed the non-Hermitian skin effect, represents a fundamental aspect of non-Hermitian systems. While it endows non-Hermitian systems with unprecedented physical…

Mesoscale and Nanoscale Physics · Physics 2025-01-30 Nan Cheng , Chang Shu , Kai Zhang , Xiaoming Mao , Kai Sun

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

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

The past decades have witnessed an explosion of interest in topological materials, and a lot of mathematical concepts have been introduced in condensed matter physics. Among them, the bulk-boundary correspondence is the central topic in…

Mesoscale and Nanoscale Physics · Physics 2023-03-29 Nobuyuki Okuma , Masatoshi Sato

The non-Hermitian skin effect is a phenomenon in which an extensive number of states accumulates at the boundaries of a system. It has been associated to nontrivial topology, with nonzero bulk invariants predicting its appearance and its…

Mesoscale and Nanoscale Physics · Physics 2025-09-24 Helene Spring , Viktor Könye , Anton R. Akhmerov , Ion Cosma Fulga

Parity-time (PT) symmetry and anti-PT symmetry have attracted extensive interest for their non-Hermitian spectral properties, particularly the emergence of purely real and imaginary eigenvalues in their symmetry-unbroken regime,…

The non-Hermitian skin effect refers to the accumulation of eigenstates near the boundary in open boundary lattice models, which can be systematically characterized using the non-Bloch band theory. Here, we apply the non-Bloch band theory…

Quantum Physics · Physics 2024-09-11 Bo Li , He-Ran Wang , Fei Song , Zhong Wang

We investigate novel features of three dimensional non-Hermitian Weyl semimetals, paying special attention to its unconventional bulk-boundary correspondence. We use the non-Bloch Chern numbers as the tool to obtain the topological phase…

Mesoscale and Nanoscale Physics · Physics 2019-04-05 Xiaosen Yang , Yang Cao , Yunjia Zhai

Bulk-boundary correspondence, connecting the bulk topology and the edge states, is an essential principle of the topological phases. However, the bulk-boundary correspondence is broken down in general non-Hermitian systems. In this paper,…

Mesoscale and Nanoscale Physics · Physics 2021-02-24 Yang Cao , Yang Li , Xiaosen Yang