Single charge sensing and transport in double quantum dots fabricated from commercially grown Si/SiGe heterostructures

TL;DR

This study evaluates commercially grown Si/SiGe heterostructures for quantum dot applications, demonstrating high mobility electron gases and successful single charge detection in double quantum dots at millikelvin temperatures.

Contribution

It shows that commercially available Si/SiGe heterostructures can be optimized for quantum dot devices with high mobility and effective charge sensing capabilities.

Findings

Charge densities of 1-3 x 10^{11}/cm^2 achieved

Electron mobilities exceed 100,000 cm^2/Vs

Single charge transitions observed in double quantum dots

Abstract

We perform quantum Hall measurements on three types of commercially available modulation doped Si/SiGe heterostructures to determine their suitability for depletion gate defined quantum dot devices. By adjusting the growth parameters, we are able to achieve electron gases with charge densities 1-3 X 10^{11}/cm^2 and mobilities in excess of 100,000 cm^2/Vs. Double quantum dot devices fabricated on these heterostructures show clear evidence of single charge transitions as measured in dc transport and charge sensing and exhibit electron temperatures of 100 mK in the single quantum dot regime.