Aharonov-Bohm oscillations in Dirac semimetal Cd3As2 nanowires

TL;DR

This paper reports the observation of Aharonov-Bohm oscillations in Cd3As2 nanowires, providing direct transport evidence of topological surface states in three-dimensional Dirac semimetals and demonstrating control via Fermi level tuning.

Contribution

It presents the first transport evidence of surface states in 3D Dirac semimetals through Aharonov-Bohm oscillations in nanowires, with tunable quantum transport properties.

Findings

Observation of Aharonov-Bohm oscillations in Cd3As2 nanowires

Transport evidence of topological surface states

Fermi level tuning modulates quantum transport

Abstract

Three-dimensional Dirac semimetals, a three-dimensional analogue of graphene, are unusual quantum materials with massless Dirac fermions, which can be further converted to Weyl fermions by breaking time reversal or inversion symmetry. Topological surface states with Fermi arcs are predicted on the surface and have been observed by angle-resolved photoemission spectroscopy experiments. Although the exotic transport properties of the bulk Dirac cones have been demonstrated, it is still a challenge to reveal the surface states via transport measurements due to the highly conductive bulk states. Here, we show Aharonov-Bohm oscillations in individual single-crystal Cd3As2 nanowires with low carrier concentration and large surface-to-volume ratio, providing transport evidence of the surface state in three-dimensional Dirac semimetals. Moreover, the quantum transport can be modulated by tuning the Fermi level using a gate voltage, enabling a deeper understanding of rich physics residing in Dirac semimetals.