Additional Evidence for the Surface Origin of the Peculiar Angular-Dependent Magnetoresistance Oscillations Discovered in a Topological Insulator Bi_{1-x}Sb_{x}

TL;DR

This study provides evidence that the unusual angular-dependent magnetoresistance oscillations in Bi_{1-x}Sb_{x} are primarily surface-originated, likely involving coupling between surface and bulk states, revealing new insights into topological insulator surface phenomena.

Contribution

It offers direct experimental evidence linking the oscillations to surface states and proposes a new mechanism involving surface-bulk coupling in topological insulators.

Findings

Oscillations originate from surface states.

Symmetry suggests (111) plane involvement.

Surface-bulk coupling mechanism proposed.

Abstract

We present detailed data on the unusual angular-dependent magnetoresistance oscillation phenomenon recently discovered in a topological insulator Bi_{0.91}Sb_{0.09}. Direct comparison of the data taken before and after etching the sample surface gives compelling evidence that this phenomenon is essentially originating from a surface state. The symmetry of the oscillations suggests that it probably comes from the (111) plane, and obviously a new mechanism, such as a coupling between the surface and the bulk states, is responsible for this intriguing phenomenon in topological insulators.