Direct control of the tunnel splitting in a one-electron double quantum dot

TL;DR

This paper demonstrates direct measurement and tunability of the tunnel splitting in a one-electron double quantum dot using transport measurements and gate voltage adjustments.

Contribution

It provides a method to directly measure and control the tunnel splitting in a double quantum dot, advancing quantum dot manipulation techniques.

Findings

Measured the tunnel splitting via anticrossing features.

Showed tunability of tunnel coupling with gate voltages.

Demonstrated magnetic field influence on tunnel splitting.

Abstract

Quasi-static transport measurements are employed on a laterally defined tunnel-coupled double quantum dot. A nearby quantum point contact allows us to track the charge as added to the device. If charged with only up to one electron, the low-energy spectrum of the double quantum dot is characterized by its quantum mechanical interdot tunnel splitting. We directly measure its magnitude by utilizing particular anticrossing features in the stability diagram at finite source-drain bias. By modification of gate voltages defining the confinement potential as well as by variation of a perpendicular magnetic field we demonstrate the tunability of the coherent tunnel coupling.