Ambi-chiral anomalous Hall effect in magnetically doped topological insulators

TL;DR

This study investigates the anomalous Hall effect in magnetically doped topological insulators, revealing how film thickness influences the chirality of the Hall loops and proposing a model for magnetic order evolution.

Contribution

It introduces a phenomenological model explaining the evolution of Hall effect chirality in Mn- and Cr-doped topological insulators based on film thickness and doping.

Findings

Mn-doped Bi2Te3 shows strengthened clockwise Hall chirality with reduced thickness

Cr-doped Bi2Te3 exhibits enhanced counterclockwise Hall chirality as thickness decreases

A model explains the relationship between magnetic order and Hall effect chirality

Abstract

The chirality associated with broken time reversal symmetry in magnetically doped topological insulators has important implications to the quantum transport phenomena. Here we report the anomalous Hall effect studies in Mn- and Cr-doped Bi$_2$Te$_3$ topological insulators with varied thickness and doping content. By tracing the chirality of the Hall loops, we find that the Mn-type anomalous Hall effect with clockwise chirality is strengthened by the reduction of film thickness, which is opposite to that of the Cr-type anomalous Hall effect with counterclockwise chirality. We provide a phenomenological model to explain the evolution of magnetic order and anomalous Hall effect chirality in magnetically doped topological insulators.