Primary thermometry in the intermediate Coulomb blockade regime

TL;DR

This paper demonstrates that Coulomb blockade thermometers can be accurately extended into lower temperature regimes by applying theoretical corrections, enhancing measurement precision without losing their primary status.

Contribution

It experimentally validates that theoretical corrections enable accurate primary thermometry in the intermediate Coulomb blockade regime.

Findings

Extended the operational temperature range of CBT sensors.

Validated theoretical corrections improve measurement accuracy.

Maintained primary thermometry standards in new regime.

Abstract

We investigate Coulomb blockade thermometers (CBT) in an intermediate temperature regime, where measurements with enhanced accuracy are possible due to the increased magnitude of the differential conductance dip. Previous theoretical results show that corrections to the half width and to the depth of the measured conductance dip of a sensor are needed, when leaving the regime of weak Coulomb blockade towards lower temperatures. In the present work, we demonstrate experimentally that the temperature range of a CBT sensor can be extended by employing these corrections without compromising the primary nature or the accuracy of the thermometer.