Nonlocal thermoelectricity in a Cooper-pair splitter

TL;DR

This paper explores nonlocal thermoelectric effects in a Cooper-pair splitter, revealing how nonlocal coupling induces thermoelectric currents and heat exchange, with potential applications in power generation and cooling.

Contribution

It demonstrates the emergence of nonlocal thermoelectric phenomena in a double-quantum-dot-superconductor setup, highlighting conditions for power generation and cooling.

Findings

Nonlocal thermoelectric effects arise from particle-hole symmetry breaking.

Cooper-pair splitting can generate thermo-currents without charge transfer.

Nonlocal heat exchange is mediated by Andreev reflection.

Abstract

We investigate the nonlocal thermoelectric transport in a Cooper-pair splitter based on a double-quantum-dot-superconductor three-terminal hybrid structure. We find that the nonlocal coupling between the superconductor and the quantum dots gives rise to nonlocal thermoelectric effects which originate from the nonlocal particle-hole breaking of the system. We show that Cooper-pair splitting induces the generation of a thermo-current in the superconducting lead without any transfer of charge between the two normal metal leads. Conversely, we show that a nonlocal heat exchange between the normal leads is mediated by non-local Andreev reflection. We discuss the influence of finite Coulomb interaction and study under which conditions nonlocal power generation becomes possible, and when the Cooper-pair splitter can be employed as a cooling device.