Aharonov-Bohm interference in topological insulator nanoribbons

TL;DR

This paper provides transport evidence of topological surface states in Bi2Se3 nanoribbons through Aharonov-Bohm oscillations, demonstrating their robustness and potential for spintronic applications.

Contribution

It presents the first clear transport demonstration of topological surface states in Bi2Se3 nanoribbons via quantum interference effects.

Findings

Observation of pronounced Aharonov-Bohm oscillations in magnetoresistance

Dominance of the primary h/e oscillation indicating surface state coverage

Robustness of surface states up to room temperature

Abstract

Topological insulators represent novel phases of quantum matter with an insulating bulk gap and gapless edges or surface states. The two-dimensional topological insulator phase was predicted in HgTe quantum wells and confirmed by transport measurements. Recently, Bi2Se3 and related materials have been proposed as three-dimensional topological insulators with a single Dirac cone on the surface and verified by angle-resolved photoemission spectroscopy experiments. Here, we show unambiguous transport evidence of topological surface states through periodic quantum interference effects in layered single-crystalline Bi2Se3 nanoribbons. Pronounced Aharonov-Bohm oscillations in the magnetoresistance clearly demonstrate the coverage of two-dimensional electrons on the entire surface, as expected from the topological nature of the surface states. The dominance of the primary h/e oscillation and its temperature dependence demonstrate the robustness of these electronic states. Our results suggest that topological insulator nanoribbons afford novel promising materials for future spintronic devices at room temperature.