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Main Authors: Wang, Qing, Hao, Ning
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2407.00795
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author Wang, Qing
Hao, Ning
author_facet Wang, Qing
Hao, Ning
contents The Su-Schrieffer-Heeger (SSH) model is a fundamental lattice model used to study topological physics. Here, we propose a new versatile one-dimensional (1D) lattice model that extends beyond the SSH model. Our 1D model breaks chiral symmetry and has generalized topology characterized by a projected winding number $W_{1D,P}=1$. When this model is extended to 2D, it can generate a second-order topological insulator (SOTI) phase. The generalized topology of the SOTI phase is protected by a pair of opposite winding numbers $W_{2D,P}^{\pm}=\pm1$, which count the opposite phase windings of a projected vortex and antivortex pair defined in the manifold of the entire parameter space. Thus, the topology of our models is robust and the end (corner) modes are independent of the selection of unit cells and boundary configurations. More significantly, we demonstrate that the model is very general and can be inherently realized in many categories of crystalline materials such as BaHCl.
format Preprint
id arxiv_https___arxiv_org_abs_2407_00795
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Generalized Topology in Lattice Models without Chiral Symmetry
Wang, Qing
Hao, Ning
Mesoscale and Nanoscale Physics
Materials Science
The Su-Schrieffer-Heeger (SSH) model is a fundamental lattice model used to study topological physics. Here, we propose a new versatile one-dimensional (1D) lattice model that extends beyond the SSH model. Our 1D model breaks chiral symmetry and has generalized topology characterized by a projected winding number $W_{1D,P}=1$. When this model is extended to 2D, it can generate a second-order topological insulator (SOTI) phase. The generalized topology of the SOTI phase is protected by a pair of opposite winding numbers $W_{2D,P}^{\pm}=\pm1$, which count the opposite phase windings of a projected vortex and antivortex pair defined in the manifold of the entire parameter space. Thus, the topology of our models is robust and the end (corner) modes are independent of the selection of unit cells and boundary configurations. More significantly, we demonstrate that the model is very general and can be inherently realized in many categories of crystalline materials such as BaHCl.
title Generalized Topology in Lattice Models without Chiral Symmetry
topic Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2407.00795