Gate-tuned Aharonov-Bohm interference of surface states in a quasi-ballistic Dirac semimetal nanowire

TL;DR

This paper demonstrates gate-tuned Aharonov-Bohm interference in a quasi-ballistic Dirac semimetal nanowire, revealing topologically protected surface state transport through conductance oscillations and phase shifts.

Contribution

It reports the first observation of gate-controlled topological Aharonov-Bohm oscillations in a Dirac semimetal nanowire, highlighting the topological nature of surface states.

Findings

Gate voltage induces conductance oscillations without magnetic field.

Periodic π phase-shift of Aharonov-Bohm oscillations observed.

Topological surface state transport confirmed by nonlocal measurements.

Abstract

We report an observation of a topologically protected transport of surface carriers in a quasi-ballistic Cd3As2 nanowire.The nanowire is thin enough for the spin-textured surface carriers to form 1D subbands, demonstrating conductance oscillations with gate voltage even without magnetic field. The {\pi} phase-shift of Aharonov-Bohm oscillations can periodically appear or disappear by tuning gate voltage continuously. Such a {\pi} phase shift stemming from the Berry's phase demonstrates the topological nature of surface states.The topologically protected transport of the surface states is further revealed by four-terminal nonlocal measurements.