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We show that the bulk-boundary correspondence for topological insulators can be modified in the presence of non-Hermiticity. We consider a one-dimensional tight-binding model with gain and loss as well as long-range hopping. The system is…

Quantum Physics · Physics 2016-04-04 Tony E. Lee

Recent studies of disorder or non-Hermiticity induced topological insulators inject new ingredients for engineering topological matter. Here we consider the effect of purely non-Hermitian disorders, a combination of these two ingredients,…

Mesoscale and Nanoscale Physics · Physics 2022-12-12 Xi-Wang Luo , Chuanwei Zhang

Parity-time (PT) symmetry and broken in micro/nano photonic structures have been investigated extensively as they bring new opportunities to control the flow of light based on non-Hermitian optics. Previous studies have focused on the…

Optics · Physics 2022-07-20 Qi Zhang , Yun Ma , Qi Liu , Xinchen Zhang , Yali Jia , Limin Tong , Qihuang Gong , Ying Gu

Topological phenomena in non-Hermitian systems have recently become a subject of great interest in the photonics and condensed-matter communities. In particular, the possibility of observing topologically-protected edge states in…

Mesoscale and Nanoscale Physics · Physics 2020-04-02 Pablo Reséndiz-Vázquez , Konrad Tschernig , Armando Perez-Leija , Kurt Busch , Roberto de J. León-Montiel

We investigate localization-delocalization transition in one-dimensional non-Hermitian quasiperiodic lattices with exponential short-range hopping, which possess parity-time ($\mathcal{PT}$) symmetry. The localization transition induced by…

Disordered Systems and Neural Networks · Physics 2020-05-27 Yanxia Liu , Xiang-Ping Jiang , Junpeng Cao , Shu Chen

Understanding the interplay of non-Hermiticity and topology is crucial given the intrinsic openness of most natural and engineered systems and it has important ramifications in topological lasers and sensors. Intense efforts have been…

Despite its non-Hermitian nature, the transverse optical beam shift exhibits both real eigenvalues and non-orthogonal eigenstates. To explore this unexpected similarity to typical PT (parity-time)-symmetric systems, we first categorize the…

Non-Hermitian point gap (NHPG) is a unique phenomenon in non-Hermitian systems and induces non-Hermitian skin effect (NHSE). In photonic crystals, NHPG and the NHSE have previously been explored mainly through material loss, where the…

In recent years, non-Hermitian phases in classical and quantum systems have garnered significant attention. In particular, their intriguing band geometry offers a platform for exploring unique topological states and unconventional quantum…

Mesoscale and Nanoscale Physics · Physics 2023-10-10 Ayan Banerjee , Arka Bandyopadhyay , Ronika Sarkar , Awadhesh Narayan

Understanding the wave transport and localisation is a major goal in the study of lattices of different nature. In general, inhibiting the energy transport on a perfectly periodic and disorder-free system is challenging, however, some…

The non-Hermitian skin effect is an intriguing physical phenomenon, in which all eigen-modes of a non-Hermitian lattice become localized at boundary regions. While such an exotic behavior has been demonstrated in various physical platforms,…

Applied Physics · Physics 2025-01-27 Mathieu Padlewski , Romain Fleury , Hervé Lissek

The concept of flat band plays an important role in strongly-correlated many-body physics. However, the demonstration of the flat band physics is highly nontrivial due to intrinsic limitations in conventional condensed matter materials.…

Quantum Physics · Physics 2016-06-29 Zi-He Yang , Yan-Pu Wang , Zheng-Yuan Xue , Wan-Li Yang , Yong Hu , Jin-Hua Gao , Ying Wu

Non-Hermitian systems exhibit anomalous scaling, a striking departure from conventional bulk laws, rooted in the non-Hermitian skin effect (NHSE). Here, we experimentally uncover this scaling and demonstrate its active control in a temporal…

Optics · Physics 2026-03-30 Shulin Wang , Jiawei He , Zhiyuan Yang , Stefano Longhi , Peng Xue

The non-Hermitian skin effect (NHSE) and nonlinearity can both delocalize topological modes (TMs) from the interface. However, the NHSE requires precise parameter tuning, while nonlinearity in Hermitian systems results in partial…

Quantum Physics · Physics 2025-09-03 Zhao-Fan Cai , Yu-Chun Wang , Yu-Ran Zhang , Tao Liu , Franco Nori

We investigate a one-dimensional tight-binding lattice with asymmetrical couplings and various type of nonlinearities to study nonlinear non-Hermitian skin effect. Our focus is on the exploration of nonlinear skin modes through a…

Pattern Formation and Solitons · Physics 2025-05-15 C. Yuce

We demonstrate mesoscopic transport through quantum states in quasi-1D lattices maintaining the combination of parity and time-reversal symmetries by controlling energy gain and loss. We investigate the phase diagram of the non-Hermitian…

Quantum Physics · Physics 2017-08-30 Jung-Wan Ryu , Nojoon Myoung , Hee Chul Park

We study the broadening of initially localized wave packets in a quasi one-dimensional diamond ladder with interacting, spinless fermions. The lattice possesses a flat band causing localization. We place special focus on the transition away…

Statistical Mechanics · Physics 2024-06-04 Mirko Daumann , Thomas Dahm

Unique and flexible properties of non-Hermitian photonic systems attract ever-increasing attention via delivering a whole bunch of novel optical effects and allowing for efficient tuning light-matter interactions on nano- and microscales.…

Non-Hermitian systems exploiting the synergy between gain and loss have recently become the focus of interest to discover novel physical phenomena. The spatial symmetry breaking in such systems allows tailoring the wave propagation at will.…

Optics · Physics 2020-10-14 W. W. Ahmed , R. Herrero , M. Botey , Y. Wu , K. Staliunas

The type-II Dirac cone is a special feature of the band structure, whose Fermi level is represented by a pair of crossing lines. It has been demonstrated that such a structure is useful for investigating topological edge solitons, and more…

Optics · Physics 2024-09-09 Qian Tang , Milivoj R. Belić , Hua Zhong , Meng Cao , Yongdong Li , Yiqi Zhang