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Related papers: Non-Hermitian Higher-Order Dirac Semimetals

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Non-Hermitian nodal knot metals (NKMs) contains intricate complex-valued energy bands gives rise to knotted exceptional loops and new topological surface states. We introduce a formalism that connects the algebraic, geometric, and…

Mesoscale and Nanoscale Physics · Physics 2021-03-02 Xiao Zhang , Guangjie Li , Yuhan Liu , Tommy Tai , Ronny Thomale , Ching Hua Lee

The ideas of topology have found tremendous success in Hermitian physical systems, but even richer properties exist in the more general non-Hermitian framework. Here, we theoretically propose and experimentally demonstrate a new…

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

We introduce topological skyrmion semimetal phases of matter, characterized by bulk electronic structures with topological defects in ground state observable textures over the Brillouin zone (BZ), rather than topological degeneracies in…

Mesoscale and Nanoscale Physics · Physics 2023-11-28 Shu-Wei Liu , Joe H. Winter , A. M. Cook

The interplay between symmetry and topological properties plays a very important role in modern physics. In the past decade, the concept of symmetry-enriched topological (SET) phases was proposed and their classifications have been…

Strongly Correlated Electrons · Physics 2026-02-16 Jing-Ren Zhou , Zheng-Cheng Gu

In this article, we have introduced a $\mathcal{PT}$ symmetric non-Hermitian Hamiltonian model which is given as $\hat{\mathcal{H}}=\omega (\hat{b}^{\dag}\hat{b}+1/2)+ \alpha (\hat{b}^{2}-(\hat{b}^{\dag})^{2})$ where $\omega$ and $\alpha$…

Mathematical Physics · Physics 2015-06-12 O. Yesiltas

Discovering Dirac fermions with novel properties has become an important front in condensed matter and materials sciences. Here, we report the observation of unusual Dirac fermion states in a strongly-correlated electron setting, which are…

We investigate the interplay between non-Hermitian skin effect (NHSE) and topological properties in two-dimensional topological superconductor. Two kinds of non-Hermiticity are considered. The first is the spin-independent non-reciprocal…

Superconductivity · Physics 2024-11-13 Hong Wang , Ming Lu , Jie Liu

We examine a non-Hermitian (NH) tight-binding system comprising of two orbitals per unit cell and their electrical circuit analogues. We distinguish the PT-symmetric and non-PT symmetric cases characterised by non-reciprocal nearest…

Mesoscale and Nanoscale Physics · Physics 2024-03-11 Dipendu Halder , Ronny Thomale , Saurabh Basu

Emergence of exceptional points in two dimensions is one of the remarkable phenomena in non-Hermitian systems. We here elucidate the impacts of symmetry on the non-Hermitian physics. Specifically, we analyze chiral symmetric correlated…

Strongly Correlated Electrons · Physics 2019-03-13 Tsuneya Yoshida , Robert Peters , Norio Kawakami , Yasuhiro Hatsugai

Non-Hermitian (NH) Hamiltonians have become an important asset for the effective description of various physical systems that are subject to dissipation. Motivated by recent experimental progress on realizing the NH counterparts of gapless…

Mesoscale and Nanoscale Physics · Physics 2019-01-30 Jan Carl Budich , Johan Carlström , Flore K. Kunst , Emil J. Bergholtz

We proposed that BaHgSn is a Dirac semimetal (DSM) which can host hourglass-like surface states (HSSs) as protected by nonsymmorphic glide symmetry. Compared to KHgSb, an isostructural topological crystalline insulator with the same HSSs,…

Materials Science · Physics 2020-04-08 Tan Zhang , Zhihai Cui , Zhijun Wang , Hongming Weng , Zhong Fang

We study a bipartite Kronig-Penney model with negative Dirac-delta potentials that may be used, amongst other models, to interpret plasmon propagation in nanoparticle arrays. Such a system can be mapped into a Su-Schrieffer-Heeger-like…

Mesoscale and Nanoscale Physics · Physics 2020-10-15 Thomas Benjamin Smith , Alessandro Principi

Non-Hermitian matrices are ubiquitous in the description of nature ranging from classical dissipative systems, including optical, electrical, and mechanical metamaterials, to scattering of waves and open quantum many-body systems. Seminal…

Mesoscale and Nanoscale Physics · Physics 2024-07-08 Kang Yang , Zhi Li , J. Lukas K. König , Lukas Rødland , Marcus Stålhammar , Emil J. Bergholtz

The layered WHM - type (W=Zr/Hf/La, H=Si/Ge/Sn/Sb, M=S/Se/Te) materials represent a large family of topological semimetals, which provides an excellent platform to study the evolution of topological semimetal state with the fine tuning of…

Materials Science · Physics 2018-04-04 Jin Hu , Yanglin Zhu , David Graf , Zhijie Tang , Zhiqiang Mao

The emergent higher-order topological insulators significantly deepen our understanding of topological physics. Recently, the study has been extended to topological semimetals featuring gapless bulk band nodes. To date, higherorder nodal…

Materials Science · Physics 2023-11-30 Huahui Qiu , Yuzeng Li , Qicheng Zhang , Chunyin Qiu

Topological phases and transitions are of fundamental importance in physics, which provide a deep insight into the understanding of materials. Recently, non-Abelian topological transitions have been investigated in Hermitian systems,…

Quantum Physics · Physics 2025-03-25 Yunhan Wang , Yang Wu , Xiangyu Ye , Chang-Kui Duan , Ya Wang , Haiping Hu , Xing Rong , Jiangfeng Du

Recent experimental advances in controlling dissipation have brought about unprecedented flexibility in engineering non-Hermitian Hamiltonians in open classical and quantum systems. A particular interest centers on the topological…

Mesoscale and Nanoscale Physics · Physics 2018-09-25 Zongping Gong , Yuto Ashida , Kohei Kawabata , Kazuaki Takasan , Sho Higashikawa , Masahito Ueda

We show that the chiral Dirac and Majorana hinge modes in three-dimensional higher-order topological insulators (HOTIs) and superconductors (HOTSCs) can be gapped while preserving the protecting $\mathsf{C}_{2n}\mathcal T$ symmetry upon the…

Strongly Correlated Electrons · Physics 2020-02-20 Apoorv Tiwari , Ming-Hao Li , B. A. Bernevig , Titus Neupert , S. A. Parameswaran

We propose helical topological superconductivity away from the Fermi surface in three-dimensional time-reversal-symmetric odd-parity multiband superconductors. In these systems, pairing between electrons originating from different bands is…

Mesoscale and Nanoscale Physics · Physics 2024-07-01 Masoud Bahari , Song-Bo Zhang , Chang-An Li , Sang-Jun Choi , Philipp Rüßmann , Carsten Timm , Björn Trauzettel