Aharonov Bohm effect in 2D topological insulator

TL;DR

This paper reports magnetotransport experiments on HgTe quantum wells, revealing Aharonov-Bohm oscillations linked to edge states in a 2D topological insulator, highlighting the role of charge puddles.

Contribution

It demonstrates the observation of Aharonov-Bohm effects in 2D topological insulators through magnetotransport measurements, emphasizing the influence of charge puddles.

Findings

Negative magnetoresistance observed in local and nonlocal measurements

Periodic oscillations damping with magnetic field detected

Charge puddles of about 100 nm size influence edge states

Abstract

We present magnetotransport measurements in HgTe quantum well with inverted band structure, which expected to be a two-dimensional topological insulator having the bulk gap with helical gapless states at the edge. The negative magnetoresistance is observed in the local and nonlocal resistance configuration followed by the periodic oscillations damping with magnetic field. We attribute such behaviour to Aharonov-Bohm effect due to magnetic flux through the charge carrier puddles coupled to the helical edge states. The characteristic size of these puddles is about 100 nm.