Drastic enhancement of the thermal Hall angle in a d -wave superconductor

Abstract

A drastic enhancement of the thermal Hall angle in d-wave superconductors was observed experimentally in a cuprate superconductor and in CeCoIn 5 at low temperatures and very weak magnetic field [Phys. Rev. Lett. 86, 890 (2001); Phys. Rev. B 72, 214515 (2005)]. However, to the best of our knowledge, its microscopic calculation has not been performed yet. To study this microscopically, we derive the thermal Hall coefficient in extreme type-II superconductors with an isolated pinned vortex based on the augmented quasiclassical equations of superconductivity with the Lorentz force. Using it, we can confirm that the quasiparticle relaxation time and the thermal Hall angle are enhanced in d-wave superconductors without impurities of the resonant scattering because quasiparticles around the gap nodes which become dominant near zero temperature are restricted to the momentum in a specific orientation. This enhancement of the thermal Hall angle may also be observed in other nodal superconductors with large magnetic-penetration depth.

Charging in the vortex lattice of type-II superconductors

“…Therefore, it can be understood that the vortex-core charging due to the PPG force is caused by the anomalous Hall effect on supercurrents in the vortex state. We again emphasize that only the Lorentz force acts on supercurrents away from the vortex core and the Lorentz force may be important for transport phenomena [20,46].…”