Coulomb Blockade Thermometry Beyond the Universal Regime

Abstract

The charge localization of single electrons on mesoscopic metallic islands leads to a suppression of the electrical current, known as the Coulomb blockade. When this correction is small, it enables primary electron thermometry, as it was first demonstrated by Pekola et al. (Phys Rev Lett 73:2903, 1994). However, in the low temperature limit, random charge offsets influence the conductance and limit the universal behavior of a single metallic island. In this work, we numerically investigate the conductance of a junction array and demonstrate the extension of the primary regime for large arrays, even when the variations in the device parameters are taken into account. We find that our simulations agree well with measured conductance traces in the submillikelvin electron temperature regime.

Developing compact tuning fork thermometers for sub-mK temperatures and high magnetic fields

“…3 He melting curve thermometry 13 a) ajwoods@lanl.gov b) lucia.steinke@ufl.edu and nuclear magnetic resonance thermometers 14 have too high masses and long thermalization times to allow for measurements of small samples. Coulomb blockade thermometers show promise as ultra-low temperature thermometers [15][16][17][18] , but typically require delicate onlead magnetic demagnetization stages or on-chip cooling, which makes them incompatible or too complicated to use as sample thermometers in high magnetic fields.…”

Influence of device non-uniformities on the accuracy of Coulomb blockade thermometry

“…However it poses a source of fundamental uncertainty, which is the topic of this article. Some aspects of the problem have been addressed previously in references [9][10][11]. An experimental investigation of uncertainties in a CBT measurement itself was presented in reference [12].…”

Developing compact tuning fork thermometers for sub-mK temperatures and high magnetic fields

“…3 He melting curve thermometry 12 and nuclear magnetic resonance thermometers 13 have too high masses and long thermalization times to allow for measurements of small samples. Coulomb blockade thermometers show promise as ultra-low temperature thermometers [14][15][16][17] , but typically require delicate onlead magnetic demagnetisation stages or on-chip cooling, which makes them incompatible or too complicated to use as sample thermometers in high magnetic fields.…”