Strong nonlinear thermoelectricity generation and close-to-Carnot efficient heat engines in Superconductor-Insulator-2D electron gas junctions

TL;DR

This paper demonstrates that Superconductor-Insulator-2D electron gas junctions can efficiently generate thermoelectricity with near-Carnot efficiency, surpassing previous solid-state devices in performance and fabrication simplicity.

Contribution

It introduces a novel SISm junction that exhibits strong nonlinear thermoelectric effects and achieves record-high efficiency close to Carnot limit.

Findings

Seebeck potential up to 6.75 times the superconducting gap.

Efficiency approaching 96% of Carnot efficiency.

Superior thermoelectric performance with easier fabrication.

Abstract

We find that a novel Superconductor-Insulator-2D electron gas tunnel junction (SISm) strongly and efficiently generates thermoelectricity via a nonlinear mechanism. We simulate across the parameter space of the junction, finding and discussing different regimes with features useful for thermoelectricity generation or for specific applications. The generated Seebeck potential can go up to $6.75\Delta_0$ with a huge nonlinear Seebeck coefficient, and efficiency can get very close to Carnot efficiency $\eta=0.96\eta_C$, a record for a solid-state device model. Thermoelectric performance is far better than analogous junctions, with fewer fabrication challenges, as the device can be fabricated via standard methods.