Magnetic Proximity Effect in an Antiferromagnetic Insulator/Topological Insulator Heterostructure with Sharp Interface

TL;DR

This study demonstrates a strong magnetic proximity effect in MnSe/(Bi,Sb)2Te3 heterostructures, revealing tunable topological surface states and potential for topological spintronics applications.

Contribution

It provides the first experimental evidence of magnetic proximity effects in antiferromagnetic insulator/topological insulator heterostructures with sharp interfaces.

Findings

Hall effect measurements show significant magnetic proximity effects.

Gate voltage can tune the anomalous Hall conductance.

Proximity effects persist at low temperatures and high magnetic fields.

Abstract

We report an experimental study of electron transport properties of MnSe/(Bi,Sb)2Te3 heterostructures, in which MnSe is an antiferromagnetic insulator, and (Bi,Sb)2Te3 is a three-dimensional topological insulator (TI). Strong magnetic proximity effect is manifested in the measurements of the Hall effect and longitudinal resistances. Our analysis shows that the gate voltage can substantially modify the anomalous Hall conductance, which exceeds 0.1 e2/h at temperature of 1.6 K and magnetic field of 5 T, even though only the top TI surface is in proximity to MnSe. This work suggests that heterostructures based on antiferromagnetic insulators provide a promising platform for investigating a wide range of topological spintronic phenomena.