Fractional Topological Insulators- A Bosonization Approach

TL;DR

This paper models a metallic disk with strong spin-orbit interaction, bosonizes it to study edge states, and proposes a way to realize fractional topological insulators by tuning the chemical potential.

Contribution

It introduces a bosonization approach to fractional topological insulators in a finite disk geometry with strong spin-orbit coupling.

Findings

Edge states are described by chiral bosons.

Fractional topological insulators emerge at filling fraction 1/3.

Tuning chemical potential controls the topological phase.

Abstract

A metallic disk with strong spin orbit interaction is investigated . The finite disk geometry introduces a confining potential. Due to the strong spin-orbit interaction and confining potential the metal disk is described by an effective one dimensional with a harmonic potential. The harmonic potential gives rise to classical turning points. As a result open boundary conditions must be used. We Bosonize the model and obtain chiral Bosons for each spin on the edge of the disk. When the filling fraction is reduced to $\nu=\frac{k_{F}}{k_{so}}=\frac{1}{3}$ the electron- electron interactions are studied using the Jordan Wigner phase for composite fermions which gives rise to a Luttinger liquid. When the metallic disk is in the proximity with a superconductor a Fractional Topological Insulators is obtained. An experimental realization is proposed. We show that by tunning the chemical potential we control the classical turning points for which a Fractional Topological Insulator is realized.