Ion implanted Si:P double-dot with gate tuneable interdot coupling

TL;DR

This paper demonstrates a silicon double-dot system with tunable interdot coupling, using ion implantation and charge sensing, revealing transitions from double-dot to single-dot behavior at millikelvin temperatures.

Contribution

It introduces a phosphorus ion-implanted silicon double-dot device with gate-tunable interdot coupling, enabling detailed charge sensing independent of transport.

Findings

Interdot coupling can be tuned from weak to strong

Double-dot charging behavior observed in weak coupling regime

System behaves as a single-dot in strong coupling regime

Abstract

We report on millikelvin charge sensing measurements of a silicon double-dot system fabricated by phosphorus ion implantation. An aluminum single-electron transistor (SET) is capacitively coupled to each of the implanted dots enabling the charging behavior of the double-dot system to be studied independently of current transport. Using an electrostatic gate, the interdot coupling can be tuned from weak to strong coupling. In the weak interdot coupling regime, the system exhibits well-defined double-dot charging behavior. By contrast, in the strong interdot coupling regime, the system behaves as a single-dot.