Characterization of a topological Mott insulator in one dimension

TL;DR

This paper explores the properties of a one-dimensional topological Mott insulator, revealing how edge states evolve with interactions and introducing a novel topological transition unique to strongly correlated systems.

Contribution

It characterizes a topological Mott insulator in one dimension, demonstrating the evolution of edge states and proposing a new topological transition driven by electron correlations.

Findings

Edge states evolve from gapless to spinon states with interactions

Identification of a new topological Mott transition

Transition involves zeros of Green's function and spin gap closing

Abstract

We investigate properties of a topological Mott insulator in one dimension by examining the bulk topological invariant and the entanglement spectrum of a correlated electron model. We clarify how gapless edge states in a non-interacting topological band insulator evolve into spinon edge states in a topological Mott insulator. Furthermore, we propose a topological Mott transition, which is a new type of topological phase transition and never observed in free fermion systems. This unconventional transition occurs in spin liquid phases in the Mott insulator and is accompanied by zeros of the single-electron Green's function and a gap closing in the spin excitation spectrum.