Simulation of vortex matter two-step melting in an anisotropic superconductor with columnar defects

• Published in: Physica. C, Superconductivity Vol. 437-438; pp. 341 - 344
• Main Authors: Viana, Leonardo P., Raposo, E.P., Coutinho-Filho, M.D.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 15.05.2006; Elsevier Science
• Subjects: Columnar defects; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Flux pinning; High-Tc superconductors; Physics; Properties of type I and type II superconductors; Superconductivity; Type-II superconductivity; Vortex lattices ,flux pinning, flux creep; Vortex matter; 74.25.Qt; Flux pinning; 74.40.+k; 64.70.−p; High-Tc superconductors; 74.25.−q; Vortex matter; Columnar defects; Type-II superconductivity; 74.72.−h; 74.72.Hs; Type-II superconductors; Vortex glass; 74.25.Qt; 74.40.+k; 74.25.-q; 74.72.-h; 74.72.Hs; 64.70.-p; Magnetic field effects; Bismuth oxides; Bose glass; Abrikosov theory; Calcium oxides; Strontium oxides; Monte Carlo methods; Order degree; Vortices; Vortex matter; Flux pinning; Columnar defects; Type-II superconductivity; High-Tc superconductors; Vortex liquids; Copper oxides
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/j.physc.2005.12.044

Columnar defects in high-temperature superconductors have been object of recent intense experimental and theoretical investigations. We report on the observation of a melting in two steps in a 3D vortex line system with randomly-placed columnar defects. We perform a Monte Carlo simulation using the Lawrence–Doniach model, with Bi2Sr2CaCu2O8 parameters, in a magnetic field applied perpendicular to the CuO2 planes and parallel to the columnar defects. The Bose glass phase observed at low temperatures melts, as the temperature increases, through two steps: first it depins to a distorted Abrikosov lattice, in which the vortex matter presents some degree of hexatic order; in the sequence, further increment in the temperature causes the fusion of this distorted lattice.