Numerical eigenstates for a two-antidot channel under a magnetic field

Abstract

We have calculated the single-particle eigenstates of a system designed to model a two-dimensional channel obstructed by a pair of anti-dots, under a transverse magnetic field. The model is relevant to recent experiments in which the conductance of the two-antidot system reveals a conductance minimum which is modulated by oscillations of a constant period in a magnetic field, contrary to the predictions of semiclassical calculations. We show that the modulations are due to the evolution with applied magnetic field of the eigenstates occupying the Fermi level, which alternate between cyclotron resonant states and states which are pinched off in the constricted region between the antidots and the channel edge. The phenomenon is an example of the interplay of the semiclassical cyclotron behavior and the quantum-mechanical nature of the constrictions.