Phase-tunable colossal magneto-heat resistance in ferromagnetic Josephson thermal valves

TL;DR

This paper introduces a Josephson thermal valve that exhibits colossal magneto-heat resistance, allowing precise control of heat flow at the nanoscale through phase and magnetic alignment tuning.

Contribution

It predicts a giant magneto-heat resistance effect in ferromagnetic Josephson junctions, combining phase control and magnetic alignment for advanced heat management.

Findings

Colossal magneto-heat resistance ratios up to 10^7% predicted.

Heat conductance depends strongly on exchange field alignment.

Quantum phase control adds an extra degree of freedom for thermal regulation.

Abstract

We propose a heat valve based on the interplay between thermal transport and proximity-induced exchange splitting in Josephson tunnel junctions. We demonstrate that the junction heat conductance strongly depends on the relative alignment of the exchange fields induced in the superconductors. Colossal magneto-heat resistance ratios as large as 10^7% are predicted to occur under proper temperature and phase conditions, as well as suitable ferromagnet-superconductor combinations. Moreover, the quantum phase tailoring, intrinsic to the Josephson coupling, offers an additional degree of freedom for the control of the heat conductance. Our predictions for the phase-coherent and spin-dependent tuning of the thermal flux can provide a useful tool for heat management at the nanoscale.