Charge Offset Drift in Silicon Single Electron Devices: Geometrical Considerations

Single electron devices (SEDs) have applications in metrology and quantum computing. Using SEDs necessitates stability in the operating point. The low-frequency stability of a SED can be quantified with a measurement of charge offset drift. One of the difficulties that arises with these types of measurements is differentiating between drift inherent in the device and extrinsic drift caused by the measurement setup. To this end, measurements of nominally identical devices were carried out using different cryogenic and electronic systems. In addition to verifying that the measured drifts are the result of the SEDs, our measurements confirm a gate design dependence of charge offset drift. Combined with the previously observed materials dependence this design dependence provides the first steps toward a more complete picture of what influences low-frequency charge noise in SEDs.