CORRELATIONS IN FLUX LIQUIDS WITH WEAK DISORDER

The response of an entangled flux liquid to a quenched random potential is studied. Dense flux liquids are stable to weak disorder and will persist even if the Abrikosov flux lattice is replaced by a vortex glass at low temperatures. Disorder produces Lorentzian-squared corrections to the vortex liquid structure function that may be detectable via neutron scattering. Our results are obtained by mapping the statistical mechanics of vortex lines onto the physics of disordered bosons in two dimensions and via a simpler hydrodynamic approach. A renormalization-group analysis shows that disorder does become relevant sufficiently close to Hc1, where it is no longer screened out by thermal fluctuations. We are unable to determine if this instability leads to a vortex glass state or simply represents a crossover to new critical exponents at the lower critical field. © 1990 The American Physical Society.