Manipulation of a single charge in a double quantum dot

TL;DR

This paper demonstrates control of a single electron in a double quantum dot using microwave excitation, with measurements of charge state transitions and relaxation times, advancing quantum dot charge qubit research.

Contribution

It introduces a method for manipulating and measuring a single charge in a tunable double quantum dot with microwave excitation and charge sensing techniques.

Findings

Measured T1 relaxation time of approximately 16 ns.

Estimated lower bound for T2* dephasing time is 400 ps.

Demonstrated direct measurement of photon-induced charge state changes.

Abstract

We manipulate a single electron in a fully tunable double quantum dot using microwave excitation. Under resonant conditions, microwaves drive transitions between the (1,0) and (0,1) charge states of the double dot. Local quantum point contact charge detectors enable a direct measurement of the photon-induced change in occupancy of the charge states. From charge sensing measurements, we find T1~16 ns and a lower bound estimate for T2* of 400 ps for the charge two-level system.