Coulomb blockade thermometers (CBTs) are versatile and, in principle, primary thermometers operating down to the micro-Kelvin range but bias heating spoils the thermometry and the primary mode. Here, we introduce a method to extract the CBT electron temperature in the presence of heat created by an arbitrary bias voltage, and without assumptions on the heat flow mechanisms. The charging energy is extracted with high precision and without any other knowledge, thus making true primary thermometry possible. The experiment also reveals a subtle dependence of the charging energy on phonon temperature below 100 mK likely due to the amorphous AlOx tunnel junctions.
@article{arxiv.2502.15904,
title = {Finite-bias Coulomb blockade thermometry},
author = {Omid Sharifi Sedeh and Christian P. Scheller and Henok Weldeyesus and Taras Patlatiuk and Matthias Gramich and Jukka P. Pekola and Dominik M. Zumbühl},
journal= {arXiv preprint arXiv:2502.15904},
year = {2025}
}