A non-invasive electron thermometer based on charge sensing of a quantum dot

A. Mavalankar, S. J. Chorley, J. Griffiths, G. A. C. Jones, I. Farrer, D. A. Ritchie, C. G. Smith

Published 2013-05-29Version 1

We present a thermometry scheme to extract the temperature of a 2DEG by monitoring the charge occupation of a weakly tunnel-coupled 'thermometer' quantum dot using a quantum point contact detector. Electronic temperatures between 97 mK and 307 mK are measured by this method with an accuracy of up to 3 mK, and agree with those obtained by measuring transport through a quantum dot. The thermometer does not pass a current through the 2DEG, and can be incorporated as an add-on to measure the temperature simultaneously with another operating device. Further, the tuning is independent of temperature.