Aharonov-Bohm Effect in Three-dimensional Higher-order Topological Insulator

TL;DR

This paper demonstrates that Aharonov-Bohm oscillations in a 3D higher-order topological insulator can identify chiral hinge states, revealing universal linear relations among oscillation frequencies that are robust across sample variations.

Contribution

It introduces a novel interference model showing universal linear relations among AB oscillation frequencies in 3D HOTIs, aiding in the identification of hinge states.

Findings

AB oscillation frequencies depend on magnetic field direction

Linear relations among frequencies: ω_{x±y} = ω_x ± ω_y

Oscillation signatures are stable across sample sizes and biases

Abstract

Hinge states are the hallmark of the 3D higher-order topological insulator(HOTI). Here, we show that chiral hinge states can be identified by the magnetic field induced Aharonov-Bohm(AB) oscillation of the electron conductance in the interferometer constructed by HOTI and normal metal. Unlike AB interferometer of 3D topological insulator(TI), we find that there are different AB oscillation frequencies for a given direction of magnetic field in 3D HOTI. And the oscillation frequencies are also strongly depending on the direction of magnetic field. The main conclusion in our work is that there exists a universal linear relation between different oscillation frequencies. Here, by constructing an interference model of hinge states loops, we show both analytically and numerically that the linear relation is fulfilled in the HOTI effective model. The four basic frequencies in the work are labeled as $\omega_x$, $\omega_y$, $\omega_{x+y}$, $\omega_{x-y}$ and the main linear relations we demonstrate here are $\omega_{x\pm y}=\omega_x \pm \omega_y$. These results provide an effective way for the identification of the chiral hinge states, and the oscillation signatures are stable with different sample size and bias.