Double quantum dot with tunable coupling in an enhancement-mode silicon metal-oxide semiconductor device with lateral geometry

摘要

We present transport measurements of a tunable siliconmetal-oxide-semiconductor double quantum dot device with lateral geometry.Experimentally extracted gate-to-dot capacitances show that the device islargely symmetric under the gate voltages applied. Intriguingly, these gatevoltages themselves are not symmetric. Comparison with numerical simulationsindicates that the applied gate voltages serve to offset an intrinsic asymmetryin the physical device. We also show a transition from a large single dot totwo well isolated coupled dots, where the central gate of the device is used tocontrollably tune the interdot coupling.