Magnetoconductance signatures of chiral domain-wall bound states in magnetic topological insulators

TL;DR

This paper theoretically links butterfly-shaped hysteresis in magnetoconductance of magnetic topological insulators to chiral domain-wall bound states, proposing spatial conductance measurements to identify these states and aiding in the characterization of such materials.

Contribution

It provides a theoretical framework connecting magnetization dynamics with hysteresis and proposes a method to detect chiral domain-wall states via conductance measurements.

Findings

Link between butterfly hysteresis and domain-wall bound states established

Spatial conductance measurement can probe chirality of domain-wall states

Work aids in identifying magnetic topological insulators

Abstract

Recent magnetoconductance measurements performed on magnetic topological insulator candidates have revealed butterfly-shaped hysteresis. This hysteresis has been attributed to the formation of gapless chiral domain-wall bound states during a magnetic field sweep. We treat this phenomenon theoretically, providing a link between microscopic magnetization dynamics and butterfly hysteresis in magnetoconductance. Further, we illustrate how a spatially resolved conductance measurement can probe the most striking feature of the domain-wall bound states: their chirality. This work establishes a regime where a definitive link between butterfly hysteresis in longitudinal magneto-conductance and domain-wall bound states can be made. This analysis provides an important tool for the identification of magnetic topological insulators.