Electric polarization and discrete shift from boundary and corner charge in crystalline Chern insulators

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Zhang, Yuxuan, Barkeshli, Maissam
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866929733226201088
author Zhang, Yuxuan
Barkeshli, Maissam
author_facet Zhang, Yuxuan
Barkeshli, Maissam
contents Recently, it has been shown how topological phases of matter with crystalline symmetry and $U(1)$ charge conservation can be partially characterized by a set of many-body invariants, the discrete shift $\mathscr{S}_{\text{o}}$ and electric polarization $\vec{\mathscr{P}}_{\text{o}}$, where $\text{o}$ labels a high symmetry point. Crucially, these can be defined even with non-zero Chern number and/or magnetic field. One manifestation of these invariants is through quantized fractional contributions to the charge in the vicinity of a lattice disclination or dislocation. In this paper, we show that these invariants can also be extracted from the length and corner dependence of the total charge (mod 1) on the boundary of the system. We provide a general formula in terms of $\mathscr{S}_{\text{o}}$ and $\vec{\mathscr{P}}_{\text{o}}$ for the total charge of any subregion of the system which can include full boundaries or bulk lattice defects, unifying boundary, corner, disclination, and dislocation charge responses into a single general theory. These results hold for Chern insulators, despite their gapless chiral edge modes, and for which an unambiguous definition of an intrinsically two-dimensional electric polarization has been unclear until recently. We also discuss how our theory can fully characterize the topological response of quadrupole insulators.
format Preprint
id arxiv_https___arxiv_org_abs_2410_03821
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Electric polarization and discrete shift from boundary and corner charge in crystalline Chern insulators
Zhang, Yuxuan
Barkeshli, Maissam
Strongly Correlated Electrons
Mesoscale and Nanoscale Physics
Quantum Physics
Recently, it has been shown how topological phases of matter with crystalline symmetry and $U(1)$ charge conservation can be partially characterized by a set of many-body invariants, the discrete shift $\mathscr{S}_{\text{o}}$ and electric polarization $\vec{\mathscr{P}}_{\text{o}}$, where $\text{o}$ labels a high symmetry point. Crucially, these can be defined even with non-zero Chern number and/or magnetic field. One manifestation of these invariants is through quantized fractional contributions to the charge in the vicinity of a lattice disclination or dislocation. In this paper, we show that these invariants can also be extracted from the length and corner dependence of the total charge (mod 1) on the boundary of the system. We provide a general formula in terms of $\mathscr{S}_{\text{o}}$ and $\vec{\mathscr{P}}_{\text{o}}$ for the total charge of any subregion of the system which can include full boundaries or bulk lattice defects, unifying boundary, corner, disclination, and dislocation charge responses into a single general theory. These results hold for Chern insulators, despite their gapless chiral edge modes, and for which an unambiguous definition of an intrinsically two-dimensional electric polarization has been unclear until recently. We also discuss how our theory can fully characterize the topological response of quadrupole insulators.
title Electric polarization and discrete shift from boundary and corner charge in crystalline Chern insulators
topic Strongly Correlated Electrons
Mesoscale and Nanoscale Physics
Quantum Physics
url https://arxiv.org/abs/2410.03821