Elastic theory for the melting transition of vortex lattice in magnetic field perpendicular to the anisotropic axisQ.-M. Nie1, 2, M.-B. Luo1, 2, Q.-H. Chen2 and X. Hu1
1 Computational Materials Science Center, National Institute for Materials Science Tsukuba 305-0047, Japan
2 Department of Physics, Zhejiang University - Hangzhou 310027, PRC
received 3 January 2005; accepted in final form 8 June 2005
published online 14 July 2005
The melting transition of vortex lattice in type-II superconductors with magnetic field perpendicular to the anisotropy axis is studied in the framework of the elastic theory. It is found that the thermal fluctuations in the two directions transverse to the magnetic field are approximately proportional to each other with the constant, different from the anisotropy parameter, in a wide portion of phase diagram. One can introduce two Lindemann numbers with the ratio determined by the thermal fluctuations to draw a single melting line. The melting line thus obtained fits the experimental phase boundary quite well.
74.25.Qt - Vortex lattices, flux pinning, flux creep.
74.25.Dw - Superconductivity phase diagrams.
64.70.Dv - Solid-liquid transitions.
© EDP Sciences 2005