Charge Detection in Phosphorus-doped Silicon Double Quantum Dots

TL;DR

This paper demonstrates charge detection in phosphorus-doped silicon double quantum dots using a nearby single electron transistor, enabling observation of single-electron tunneling and charge occupancy at cryogenic temperatures.

Contribution

It introduces a method for charge detection in silicon DQDs with a SET sensor, advancing silicon-based quantum dot measurement techniques.

Findings

Detection of single-electron tunneling events

Observation of Coulomb blockade oscillations shifts

Charge occupancy states identified

Abstract

We report charge detection in degenerately phosphorus-doped silicon double quantum dots (DQD) electrically connected to an electron reservoir. The sensing device is a single electron transistor (SET) patterned in close proximity to the DQD. Measurements performed at 4.2K show step-like behaviour and shifts of the Coulomb Blockade oscillations in the detector's current as the reservoir's potential is swept. By means of a classical capacitance model, we demonstrate that the observed features can be used to detect single-electron tunnelling from, to and within the DQD, as well as to reveal the DQD charge occupancy.