Quasiparticle entropy in superconductor/normal metal/superconductor proximity junctions in the diffusive limit

TL;DR

This paper investigates the quasiparticle entropy and heat capacity in superconductor-normal metal-superconductor junctions, emphasizing the impact of the inverse proximity effect on thermodynamic properties, with implications for device design.

Contribution

It provides analytical and numerical analysis of thermodynamic quantities in S-N-S junctions, highlighting the role of the inverse proximity effect in the diffusive limit.

Findings

Inverse proximity effect significantly influences entropy and heat capacity.

Common approximations may violate thermodynamic relations.

Results aid in designing caloritronic and radiation sensors.

Abstract

We discuss the quasiparticle entropy and heat capacity of a dirty superconductor-normal metal-superconductor junction. In the case of short junctions, the inverse proximity effect extending in the superconducting banks plays a crucial role in determining the thermodynamic quantities. In this case, commonly used approximations can violate thermodynamic relations between supercurrent and quasiparticle entropy. We provide analytical and numerical results as a function of different geometrical parameters. Quantitative estimates for the heat capacity can be relevant for the design of caloritronic devices or radiation sensor applications.