Theory of bilinear magneto-electric resistance from topological-insulator surface states

TL;DR

This paper introduces a new nonlinear magnetoresistance effect called bilinear magneto-electric resistance (BMER) on topological insulator surfaces, which depends on electric and magnetic field orientation and can be used to probe spin textures.

Contribution

It theoretically predicts BMER as a novel, field-dependent nonlinear magnetoresistance effect on topological insulator surfaces, independent of ferromagnetic layers.

Findings

BMER scales linearly with electric and magnetic fields.

BMER's sign and magnitude depend on current, magnetic field, and crystal orientation.

BMER can be used to map spin textures via transport measurements.

Abstract

We theoretically investigate a new kind of nonlinear magnetoresistance on the surface of three-dimensional topological insulators (TIs). At variance with the unidirectional magnetoresistance (UMR) effect in magnetic bilayers, this nonlinear magnetoresistance does not rely on a conducting ferromagnetic layer and scales linearly with both the applied electric and magnetic fields; for this reason, we name it bilinear magneto-electric resistance (BMER). We show that the sign and the magnitude of the BMER depends sensitively on the orientation of the current with respect to the magnetic field as well as the crystallographic axes -- a property that can be utilized to map out the spin texture of the topological surface states via simple transport measurement, alternative to the angle-resolved photoemission spectroscopy (ARPES).