Flux Lattice Melting, Flux Pinning, and Superfluid Density Tensor of
R. Sasik and D. Stroud,
Department of Physics,
The Ohio State University, Columbus, Ohio 43210
We calculate the flux lattice melting curve T_M(H)
of YBa2Cu3O(7-delta) for a magnetic field H parallel to c,
in good agreement with experiment
without any free parameters. We expand the
Ginzburg-Landau order parameter in products of lowest Landau levels in the
ab plane and Bloch states in the c direction, evaluating the relevant
statistical averages by Monte Carlo simulation.
With no pinning, the c component of the superfluid density tensor
jumps to a finite value at the transition, but the transverse components
remain zero, corresponding to the sliding freedom of the flux lattice.
With pinning present, the in-plane components become
finite also. Relevant experiments are discussed.