Angle-dependent magnetothermal conductivity in d-wave superconductors

TL;DR

This paper investigates how the thermal conductivity in a quasi-two-dimensional d-wave superconductor varies with magnetic field orientation in the vortex state, revealing twofold oscillations consistent with experimental observations.

Contribution

It provides a semiclassical analysis of angle-dependent thermal conductivity in d-wave superconductors, explaining the observed oscillations in the vortex state.

Findings

Thermal conductivity shows twofold oscillations with magnetic field angle.

Oscillations are consistent with experimental data.

Analysis is valid at low temperatures in the vortex state.

Abstract

We analyse the behavior of the thermal conductivity, $\kappa(H)$, in the vortex state of a quasi-two-dimensional d-wave superconductor when both the heat current and the applied magnetic field are in the basal plane. At low temperature the effect of the field is accounted for in a semiclassical approximation, via a Doppler shift in the spectrum of the nodal quasiparticles. In that regime $\kappa(H)$ exhibits twofold oscillations as a function of the angle between the direction of the field in the plane and the direction of the heat current, in agreement with experiment.