Thermal conductivity in a mixed state of a superconductor at low magnetic fields
Abstract
We evaluate accurate low-field/low-temperature asymptotics of the thermal conductivity perpendicular to magnetic field for one-band and two-band s-wave superconductors using Keldysh-Usadel formalism. We show that heat transport in this regime is limited by tunneling of quasiparticles between adjacent vortices across a number of local points and therefore widely-used approximation of averaging over circular unit cell is not valid. In the single-band case, we obtain parameter-free analytical solution which provides theoretical lower limit for heat transport in the mixed state. In the two-band case, we show that heat transport is controlled by the ratio of gaps and diffusion constants in different bands. Presence of a weaker second band strongly enhances the thermal conductivity at low fields
Keywords
Cite
@article{arxiv.1009.3517,
title = {Thermal conductivity in a mixed state of a superconductor at low magnetic fields},
author = {A. A. Golubov and A. E. Koshelev},
journal= {arXiv preprint arXiv:1009.3517},
year = {2015}
}
Comments
7 pages, 1 figure, discussion of the clean case and discussion of experiment added