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Related papers: Systematic construction of square-root topological…

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Our contribution is two-folded. First, starting from the known fact that every real skew-Hamiltonian matrix has a real Hamiltonian square root, we give a complete characterization of the square roots of a real skew-Hamiltonian matrix W.…

Numerical Analysis · Mathematics 2012-01-25 Zhongyun Liu , Yulin Zhang , Carla Ferreira , Rui Ralha

A non-Hermitian topological insulator with real spectrum is interesting in the theory of non-Hermitian extension of topological systems. We find an experimentally realizable example of a two dimensional non-Hermitian topological insulator…

Mesoscale and Nanoscale Physics · Physics 2019-10-16 C. Yuce , H. Ramezani

We consider a compact metric graph of size $\varepsilon$, and attach to it several edges (leads) of length of order one (or of infinite length). As $\varepsilon$ goes to zero, the graph $\mathcal{G}^\varepsilon$ obtained in this way looks…

Mathematical Physics · Physics 2019-03-06 Claudio Cacciapuoti

The one-dimensional Su-Schrieffer-Heeger (SSH) model is a prototype model in the field of topological condensed matter physics, and the existence and characteristics of its topological edge states are crucial for revealing the topological…

Mesoscale and Nanoscale Physics · Physics 2025-09-23 Weibo Xu

Higher-order topological insulator (HOTI) represents a new phase of matter, the characterization of which goes beyond the conventional bulk-boundary correspondence and is attracting significant attention by the broad community. Using a…

Mesoscale and Nanoscale Physics · Physics 2020-11-17 Lingling Song , Huanhuan Yang , Yunshan Cao , Peng Yan

The Su-Schrieffer-Heeger (SSH) model describes the dynamics of spinless fermions in a one-dimensional lattice, with sublattices $A$ and $B$, and governed by staggered hopping potentials $v$ and $w$ representing the intracell and intercell…

Mesoscale and Nanoscale Physics · Physics 2024-11-13 Dyn Paulo C. Dasallas , Eduardo C. Cuansing

Using a parent Hermitian tight-binding model on a bipartite lattice with chiral symmetry, we theoretically generate non-Hermitian models for free fermions with $p$ orbitals per unit cell satisfying a complex generalization of chiral…

Mesoscale and Nanoscale Physics · Physics 2026-01-05 Edward McCann

We develop the partitioning technique for quantum discrete systems. The graph consists of several subgraphs: a central graph and several branch graphs, with each branch graph being rooted by an individual node on the central one. We show…

Quantum Physics · Physics 2011-06-27 L. Jin , Z. Song

The multipartite non-Hermitian Su-Schrieffer-Heeger model is explored as a prototypical example of one-dimensional systems with several sublattice sites for unveiling intriguing insulating and metallic phases with no Hermitian counterparts.…

Mesoscale and Nanoscale Physics · Physics 2022-05-10 Ritu Nehra , Dibyendu Roy

The topological invariant of a topological insulator (or superconductor) is given by the number of symmetry-protected edge states present at the Fermi level. Despite this fact, established expressions for the topological invariant require…

Mesoscale and Nanoscale Physics · Physics 2013-01-11 I. C. Fulga , F. Hassler , A. R. Akhmerov

The Su-Schrieffer-Heeger (SSH) model describes a one-dimensional $Z_{2}$ topological insulator, which has two topological distinct phases corresponding to two different dimerizations. When spin-orbit coupling is introduced into the SSH…

Strongly Correlated Electrons · Physics 2014-08-19 Zhongbo Yan , Shaolong Wan

The pseudo-SU(3) model is used to describe the low-energy spectra as well as $E2$ and $M1$ transition strengths in $^{158}$Gd. The Hamiltonian includes spherical single-particle energies, the quadrupole-quadrupole and proton and neutron…

Nuclear Theory · Physics 2017-08-23 G. Popa , J. P. Draayer , J. G. Hirsch

We analyze the topological and dynamical properties of a system formed by two chains of identical emitters coupled to a waveguide, whose guided modes induce all-to-all excitation hopping. We find that, in the single excitation limit, the…

Quantum Physics · Physics 2022-09-21 Ciaran McDonnell , Beatriz Olmos

We describe a method that allows for a practical application of the theory of pseudo-Hermitian operators to PT-symmetric systems defined on a complex contour. We apply this method to study the Hamiltonians $H=p^2+x^2(ix)^\nu$ with…

Quantum Physics · Physics 2007-05-23 Ali Mostafazadeh

We introduce a simple initial working system in which relations (such as part-whole) are directly represented via an architecture with operating and learning rules fundamentally distinct from standard artificial neural network methods.…

Machine Learning · Computer Science 2026-02-06 E Bowen , R Granger , A Rodriguez

The Su-Schrieffer-Heeger (SSH) model describes a paradigmatic one-dimensional (1-D) system that exhibits a non-trivial band topology. In this paper, we foreground a new scheme involving a 1-D chain of $2N+1$ Bosonic modes with…

Quantum Physics · Physics 2022-11-30 Jayakrishnan M. P. Nair

In this paper, we review the basic concepts of topologically protected edge modes using the Su Schrieffer Heeger (SSH) model, originally introduced to describe electrical conductivity in doped polyacetylene polymer chains. We then propose…

Mesoscale and Nanoscale Physics · Physics 2026-02-04 L. Q. English , A. Halchenko , F. Palmero

Topological insulators have been studied intensively over the last decades. Earlier research focused on Hermitian Hamiltonians, but recently, peculiar and interesting properties were found by introducing non-Hermiticity. In this work, we…

Statistical Mechanics · Physics 2024-05-29 Chao Chen Ye , W. L. Vleeshouwers , S. Heatley , V. Gritsev , C. Morais Smith

We predict pseudo topological insulators that have been previously overlooked. We determine some conditions under which robust pseudo topological edge states appear and illustrate our idea on the Su-Schrieffer-Heeger (SSH) model with extra…

Strongly Correlated Electrons · Physics 2019-05-21 C. Yuce

We present a rigorous but elementary index theory for a class of one-dimensional systems of interacting (and possibly disordered) fermions with $\Uone\rtimes\bbZ_2$ symmetry defined on the infinite chain. The class includes the…

Mathematical Physics · Physics 2024-07-31 Hal Tasaki