Aharonov-Bohm oscillations in the local density of topological surface states

TL;DR

This paper investigates Aharonov-Bohm oscillations in the local density of states of topological insulator and metal surfaces, revealing unique weak antilocalization effects in topological insulators detectable via spin-polarized STM.

Contribution

It demonstrates the presence of flux quantum periodicity in LDOS and identifies a novel weak antilocalization effect specific to topological insulator surfaces.

Findings

Flux quantum periodicity in total LDOS for both systems

Weak antilocalization with half flux quantum periodicity in TI surface spin components

Absence of this effect in conventional Au(111) surfaces

Abstract

We study Aharonov-Bohm (AB) oscillations in the local density of states (LDOS) for topological insulator (TI) and conventional metal Au(111) surfaces with spin-orbit interaction, which can be probed by spin-polarized scanning tunneling microscopy. We show that the spacial AB oscillatory period in the total LDOS is a flux quantum $\Phi_{0}\mathtt{=}hc/e$ (weak localization) in both systems. Remarkably, an analogous weak antilocalization with $\Phi_{0}/2$ periodic spacial AB oscillations in spin components of LDOS for TI surface is observed, while it is absent in Au(111).