Heat transport and electron cooling in ballistic normal-metal/spin-filter/superconductor junctions

TL;DR

This paper demonstrates that spin-filter effects in normal-metal/spin-filter/superconductor junctions significantly enhance electron cooling efficiency, offering promising applications in sensors, detectors, and quantum computing.

Contribution

It introduces a novel electron cooling mechanism leveraging spin-filter effects to suppress Andreev reflection, resulting in higher cooling power than traditional methods.

Findings

Cooling power is significantly increased by spin-filter effects.

Large heat extraction from normal metals is achievable.

Potential applications in quantum devices and sensors.

Abstract

We investigate electron cooling based on a clean normal-metal/spin-filter/superconductor junction. Due to the suppression of the Andreev reflection by the spin-filter effect, the cooling power of the system is found to be extremely higher than that for conventional normal-metal/nonmagnetic-insulator/superconductor coolers. Therefore we can extract large amount of heat from normal metals. Our results strongly indicate the practical usefulness of the spin-filter effect for cooling detectors, sensors, and quantum bits.