Thermopower induced by a supercurrent in superconductor-normal-metal structures

TL;DR

This paper investigates how supercurrents in superconductor-normal-metal structures can induce a finite thermopower even with electron-hole symmetry, linking thermopower to equilibrium supercurrents and structural geometry.

Contribution

It demonstrates that supercurrents can generate thermopower in N-S structures and relates this thermopower to equilibrium supercurrents, highlighting the role of geometry.

Findings

Thermopower can be finite due to supercurrents despite electron-hole symmetry.

The dominant thermopower component is directly related to equilibrium supercurrents.

Thermopower varies depending on the geometrical symmetry of the structure.

Abstract

We examine the thermopower Q of a mesoscopic normal-metal (N) wire in contact to superconducting (S) segments and show that even with electron-hole symmetry, Q may become finite due to the presence of supercurrents. Moreover, we show how the dominant part of Q can be directly related to the equilibrium supercurrents in the structure. In general, a finite thermopower appears both between the N reservoirs and the superconductors, and between the N reservoirs themselves. The latter, however, strongly depends on the geometrical symmetry of the structure.