Coherent diffraction of thermal currents in long Josephson tunnel junctions

TL;DR

This paper explores how heat transport in long Josephson tunnel junctions exhibits coherent diffraction patterns influenced by magnetic fields, vortex dynamics, and junction properties, revealing complex hysteretic behaviors.

Contribution

It introduces a detailed analysis of phase-dependent heat current diffraction in long Josephson junctions, emphasizing the importance of dynamical effects and vortex phenomena.

Findings

Heat current shows diffraction patterns similar to Josephson critical current.

Vortex formation and penetration significantly affect thermal transport.

Hysteresis occurs in diffraction patterns due to vortex trapping.

Abstract

We discuss heat transport in thermally-biased long Josephson tunnel junctions in the presence of an in-plane magnetic field. In full analogy with the Josephson critical current, the phase-dependent component of the heat current through the junction displays coherent diffraction. Thermal transport is analyzed as a function of both the length and the damping of the junction, highlighting deviations from the standard Fraunhofer pattern characteristic of short junctions. The heat current diffraction patterns show features strongly related to the formation and penetration of Josephson vortices, i.e. solitons. We show that a dynamical treatment of the system is crucial for the realistic description of the Josephson junction and it leads to peculiar results. In fact, hysteretic behaviors in the diffraction patterns when the field is swept up and down are observed, corresponding to the trapping of vortices in the junction.