Realizing and detecting a topological insulator in the AIII symmetry class

TL;DR

This paper proposes a one-dimensional model for realizing the AIII topological insulator class in ultracold atomic gases, highlights unique edge mode properties, and suggests a method to detect fractionalization through momentum distribution imaging.

Contribution

It introduces a feasible experimental model for AIII topological insulators and identifies distinctive edge mode features for fractionalization detection.

Findings

A 1D model for AIII topological insulators compatible with current experiments

Edge modes in AIII class have non-zero momentum, unlike BDI class

Fractionalization can be detected via momentum distribution imaging

Abstract

Topological insulators in the AIII symmetry class lack experimental realization. Moreover, fractionalization in one-dimensional topological insulators has not been yet directly observed. Our work might open possibilities for both challenges. We propose a one-dimensional model realizing the AIII symmetry class which can be realized in current experiments with ultracold atomic gases. We further report on a distinctive property of topological edge modes in the AIII class: in contrast to those in the well studied BDI class, they have non-zero momentum. Exploiting this feature we propose a path for the detection of fractionalization. A fermion added to an AIII system splits into two halves localized at opposite momenta, which can be detected by imaging the momentum distribution.