Conductance oscillations of antiferromagnetic layer tunnel junctions

Abstract

We study the conductance oscillation of an antiferromagnetic layer tunnel junction composed of antiferromagnetic topological insulators (MTIs) such as MnBi$_{2}$Te$_{4}$. In presence of an in-plane magnetic field, we find that the two terminal differential conductance across the junction oscillates as a function of field strength. Notably, the quantum interference at weak fields for the odd-layer MTIs is distinctive from the even-layer MTIs due to the scattering phase difference. Consequently, the differential conductance is vanishing (maximized) at integer magnetic flux quanta for even-layer (odd-layer) junction. The conductance oscillations manifest the layer-dependent quantum interference in which symmetries and scattering phases play essential roles. In numerical calculations, we observe that the quantum interference undergoes an evolution from SQUID-like patterns to Fraunhofer-like oscillations as the junction length increases.