Mixed-state quasiparticle transport in high-T_c cuprates: localization by magnetic field

Abstract

Theory of quasiparticle transport in the mixed state of a d-wave superconductor is developed under the assumption of disordered vortex array. A novel universal regime is identified at fields above H*= c*H_{c2}(T/T_c)^2, characterized by a field-independent longitudinal thermal conductivity. It is argued that this behavior is responsible for the high-field plateau in the thermal conductivity experimentally observed in cuprates by Krishana, Ong and co-workers.

4 pages REVTeX + 1 PostScript figure. Final version to appear in PRL. Several changes in response to referee comments. For related work and info visit http://www.pha.jhu.edu/~franz