Hall effect in the mixed state of clean superconductors

The Hall conductivity in the mixed state of a clean (l >> xi(0)) type-II s- wave superconductor is determined From a microscopic calculation within a q uasiclassical approximation. We find that below the superconducting transit ion the contribution to the transverse conductivity due to dynamical fluctu ations of the order parameter is compensated by a modification of the quasi particle contribution. In this regime the nonlinear behaviour of the Wall a ngle is governed by the change in the effective quasiparticle scattering ra te due to the reduction in the density of states at the Fermi level. The co nnection with experimental results is discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.