Cooling by Cooper pair splitting

TL;DR

This paper explores a Cooper pair splitter device that uses entangled electrons to achieve cooling and energy conversion, demonstrating near-thermodynamic efficiency and enabling tests of quantum correlations.

Contribution

It introduces a novel thermoelectric device based on Cooper pair splitting that functions as a refrigerator and heat engine with high efficiency.

Findings

Cooling indicates non-local quantum correlations.

Device operates as a non-local thermoelectric heat engine.

Achieves efficiencies close to thermodynamic bounds.

Abstract

The electrons forming a Cooper pair in a superconductor can be spatially separated preserving their spin entanglement by means of quantum dots coupled to both the superconductor and independent normal leads. We investigate the thermoelectric properties of such a Cooper pair splitter and demonstrate that cooling of a reservoir is an indication of non-local correlations induced by the entangled electron pairs. Moreover, we show that the device can be operated as a non-local thermoelectric heat engine. Both as a refrigerator and as a heat engine, the Cooper pair splitter reaches efficiencies close to the thermodynamic bounds. As such, our work introduces an experimentally accessible heat engine and a refrigerator driven by entangled electron pairs in which the role of quantum correlations can be tested.