title: Two-step melting of the vortex solid in layered superconductors with random columnar pins.
abstract: We consider the melting of the vortex solid in highly anisotropic layered superconductors with a small concentration of random columnar pinning centers. Using large-scale numerical minimization of a free-energy functional, we find that melting of the low-temperature, nearly crystalline vortex solid (Bragg glass) into a vortex liquid occurs in two steps as the temperature increases: the Bragg glass and liquid phases are separated by an intermediate Bose glass phase. A suitably defined local melting temperature exhibits spatial variation similar to that observed in experiments.
authors.affiliation: Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, Maryland 20742-4111, USA. cdgupta@physics.iisc.ernet.in
authors.forename: Chandan
authors.initials: C
authors.lastname: Dasgupta
authors.forename: Oriol T
authors.initials: OT
authors.lastname: Valls