Aharonov-Bohm oscillations caused by non-topological surface states in Dirac nanowires

TL;DR

This paper demonstrates that non-topological surface states in Dirac nanowires can produce Aharonov-Bohm oscillations in magnetoconductivity, similar to topological surface states, through a simple 3D Dirac model with boundary conditions.

Contribution

It introduces a model showing non-topological surface states in Dirac nanowires cause Aharonov-Bohm effects, expanding understanding beyond topological insulators.

Findings

Non-topological surface states cause Aharonov-Bohm oscillations.

Oscillation phase increases from π to 2π with magnetic field.

Surface states emerge outside the bulk gap.

Abstract

One intriguing fingerprint of surface states in topological insulators is the Aharonov-Bohm effect in magnetoconductivity of nanowires. We show that surface states in nanowires of Dirac materials (bismuth, bismuth antimony, and lead tin chalcogenides) being in non-topological phase, exhibit the same effect as amendment to magnetoconductivity of the bulk states. We consider a simple model of a cylindrical nanowire, which is described by the 3D Dirac equation with a general $T$-invariant boundary condition. The boundary condition is determined by a single phenomenological parameter whose sign defines topological-like and non-topological surface states. The non-topological surface states emerge outside the gap. In longitudinal magnetic field $B$ they lead to Aharonov-Bohm amendment for the density of states and correspondingly for conductivity of the nanowire. The phase of these magnetooscillations increases with $B$ from $\pi$ to $2\pi$.