Large Bilinear Magnetoresistance from Rashba Spin-Splitting on the Surface of a Topological Insulator

TL;DR

This paper demonstrates large bilinear magnetoresistance in Bi2Se3 topological insulator films with tunable Rashba spin-splitting, highlighting potential for spintronic device applications through surface atom manipulation.

Contribution

It reports the experimental observation of large BMR linked to Rashba spin-splitting on TI surfaces and shows how surface atom deposition tunes this effect.

Findings

BMR magnitude depends on deposited atom type and amount.

First-principles calculations confirm sizable Rashba spin-splitting.

Charge-spin interconversion can be controlled via surface modifications.

Abstract

In addition to the topologically protected linear dispersion, a band-bending-confined two-dimensional electron gas with tunable Rashba spin-splitting (RSS) was found to coexist with the topological surface states on the surface of topological insulators (TIs). Here, we report the observation of large bilinear magnetoresistance (BMR) in Bi2Se3 films decorated with transition metal atoms. The magnitude of the BMR sensitively depends on the type and amount of atoms deposited, with a maximum achieved value close to those of strong Rashba semiconductors. Our first-principles calculations reproduce the quantum well states and reveal sizable RSS in all Bi2Se3 heterostructures with broken inversion symmetry. Our results show that charge-spin interconversion through RSS states in TIs can be fine-tuned through surface atom deposition and easily detected via BMR for potential spintronic applications.