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.
@article{arxiv.1305.6881,
title = {A non-invasive electron thermometer based on charge sensing of a quantum dot},
author = {A. Mavalankar and S. J. Chorley and J. Griffiths and G. A. C. Jones and I. Farrer and D. A. Ritchie and C. G. Smith},
journal= {arXiv preprint arXiv:1305.6881},
year = {2015}
}