Time-Reversal Soliton Pairs In Even Spin-Chern-Number Higher-Order Topological Insulators

Fuente: arXiv
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Auteurs principaux: Hung, Yi-Chun, Wang, Baokai, Hsu, Chen-Hsuan, Bansil, Arun, Lin, Hsin
Format: Preprint
Publié: 2023
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author Hung, Yi-Chun
Wang, Baokai
Hsu, Chen-Hsuan
Bansil, Arun
Lin, Hsin
author_facet Hung, Yi-Chun
Wang, Baokai
Hsu, Chen-Hsuan
Bansil, Arun
Lin, Hsin
contents Solitons formed through the one-dimensional mass-kink mechanism on the edges of two-dimensional systems with non-trivial topology play an important role in the emergence of higher-order (HO) topological phases. In this connection, the existing work in time-reversal symmetric systems has focused on gapping the edge Dirac cones in the presence of particle-hole symmetry, which is not suited to the common spin-Chern insulators. Here, we address the emergence of edge solitons in spin-Chern number of $2$ insulators, in which the edge Dirac cones are gapped by perturbations preserving time-reversal symmetry but breaking spin-$U(1)$ symmetry. Through the mass-kink mechanism, we thus explain the appearance of pairwise corner modes and predict the emergence of extra charges around the corners. By tracing the evolution of the mass term along the edge, we demonstrate that the in-gap corner modes and the associated extra charges can be generated through the $S_z$-mixing spin-orbit coupling via the mass-kink mechanism. We thus provide strong evidence that an even spin-Chern-number insulator is an HO topological insulator with protected corner charges.
format Preprint
id arxiv_https___arxiv_org_abs_2303_04031
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Time-Reversal Soliton Pairs In Even Spin-Chern-Number Higher-Order Topological Insulators
Hung, Yi-Chun
Wang, Baokai
Hsu, Chen-Hsuan
Bansil, Arun
Lin, Hsin
Mesoscale and Nanoscale Physics
Solitons formed through the one-dimensional mass-kink mechanism on the edges of two-dimensional systems with non-trivial topology play an important role in the emergence of higher-order (HO) topological phases. In this connection, the existing work in time-reversal symmetric systems has focused on gapping the edge Dirac cones in the presence of particle-hole symmetry, which is not suited to the common spin-Chern insulators. Here, we address the emergence of edge solitons in spin-Chern number of $2$ insulators, in which the edge Dirac cones are gapped by perturbations preserving time-reversal symmetry but breaking spin-$U(1)$ symmetry. Through the mass-kink mechanism, we thus explain the appearance of pairwise corner modes and predict the emergence of extra charges around the corners. By tracing the evolution of the mass term along the edge, we demonstrate that the in-gap corner modes and the associated extra charges can be generated through the $S_z$-mixing spin-orbit coupling via the mass-kink mechanism. We thus provide strong evidence that an even spin-Chern-number insulator is an HO topological insulator with protected corner charges.
title Time-Reversal Soliton Pairs In Even Spin-Chern-Number Higher-Order Topological Insulators
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2303.04031