Measurement of the curvature and height of the potential barrier for a dynamic quantum dot

Abstract

We report a method to characterize the potential barrier of a dynamic quantum dot by measuring the barrier height and determining the curvature. We show that the loading statistics and hence accuracy of electron transfer through the dynamic quantum dot depend significantly on these parameters, and hence our method provides a detailed characterization of device performance. This method takes a further step towards tunable barrier shapes, which would greatly increase the accuracy of single electron sources, allowing the single electron current to be useful for quantum sensing, quantum information, and metrology. We apply our method to the case of a tunable-barrier single-electron pump, an exemplary device that shows promise as a source of hot single electron wavepackets.