Screened Vortex Lattice Model with Disorder

Giardina', C.; Priezjev, N. V.; Kosterlitz, J. M.

Screened Vortex Lattice Model with Disorder

Authors

Giardina', C.

Priezjev, N. V.

Kosterlitz, J. M.

Description

The three dimensional XY model with quenched random disorder and finite screening is studied. We argue that the system scales to model with $λ\simeq 0\simeq T$ and the resulting effective model is studied numerically by defect energy scaling. In zero external field we find that there exists a true superconducting phase with a stiffness exponent $θ\simeq +1.0$ for weak disorder. For low magnetic field and weak disorder, there is also a superconducting phase with $θ\simeq +1.0$ which we conjecture is a Bragg glass. For larger disorder or applied field, there is a non superconducting phase with $θ\simeq -1.0$. We estimate the critical external field whose value is consistent with experiment.
Extensively revised; 4 pages, 4 figures, Submitted to PRL