A robust protocol for entropy measurement in mesoscopic circuits

TL;DR

This paper presents an improved and robust protocol for measuring entropy in complex mesoscopic circuits, overcoming limitations of previous methods that depended on prior knowledge of system-specific parameters.

Contribution

It introduces a new analysis technique for entropy measurement that is applicable to more complex systems by addressing measurement scaling challenges.

Findings

Enhanced measurement accuracy for complex mesoscopic systems

Strategies for overcoming common experimental challenges

Detailed improvements to existing entropy measurement protocols

Abstract

Previous measurements utilizing Maxwell relations to measure change in entropy, $S$, demonstrated remarkable accuracy of measuring the spin-1/2 entropy of electrons in a weakly coupled quantum dot. However, these previous measurements relied upon prior knowledge of the charge transition lineshape. This had the benefit of making the determination of entropy independent of measurement scaling, but at the cost of limiting the applicability of the approach to relatively simple systems. To measure entropy of more exotic mesoscopic systems, a new analysis technique can be employed; however, doing so requires precise knowledge of the measurement scaling. Here, we give details on the necessary improvements made to the original experimental approach and highlight some of the common challenges (along with strategies to overcome them) that other groups may face when attempting this type of measurement.