Detection of fractional solitons in quantum spin Hall systems

TL;DR

This paper proposes two experimental methods to generate and detect fractional solitons in quantum spin Hall systems, using magnetic barriers and conductance measurements, advancing experimental realization of topological solitons.

Contribution

It introduces novel experimental setups for creating and detecting fractional solitons in quantum spin Hall systems, enabling practical observation of these topological excitations.

Findings

First setup shows conductance evidence of fractional solitons.

Second setup detects solitons as conductance dips without magnetization control.

Methods facilitate experimental exploration of fractional topological states.

Abstract

We propose two experimental setups that allow for the implementation and the detection of fractional solitons of the Goldstone-Wilczek type. The first setup is based on two magnetic barriers at the edge of a quantum spin Hall system for generating the fractional soliton. If then a quantum point contact is created with the other edge, the linear conductance shows evidence of the fractional soliton. The second setup consists of a single magnetic barrier covering both edges and implementing a long quantum point contact. In this case, the fractional soliton can unambiguously be detected as a dip in the conductance without the need to control the magnetization of the barrier.