Magnetoconductance switching by phase modulation in arrays of oval quantum billiards

Abstract

In this chapter we employ oval shaped quantum billiards connected by quantum wires as the building blocks of a linear quantum dot array which allows for the control of magnetoconductance in the linear response regime. In particular, we aim at a maximal finite-over zero-field ratio of the magnetoconductance, achieved by optimizing the geometry of the billiards. The switching effect arises from a relative phase change of scattering states in the single oval quantum dot through the applied magnetic field, which lifts a suppression of the transmission characteristic for a certain range of geometry parameters. A sustainable switching ratio is reached for a very low field strength, which is drastically enhanced already in the double-dot array. The impact of disorder is addressed in the form of remote impurity scattering, which poses a temperature dependent lower bound for the switching ratio.