Structure and Pinning of the Moving Vortex Matterin Type II Superconductors

Abstract

The Martin - Siggia - Rose method is applied to the time dependent Ginzburg - Landau model in the presence of both disorder and thermal fluctuations beyond linear response. This allows calculation of correlators of the order parameter, the critical current as function of magnetic field and temperature and the I-V curves. The static or moving flux line lattice in type II superconductors undergoes a transition into three disordered phases: moving vortex liquid (not pinned), homogeneous vortex glass (pinned) and crystalline Bragg glass (pinned) due to both thermal fluctuations and random quenched disorder. The location of the glass transition lien is determined and compared to experiments. The line is clearly different from both the melting line and the second peak line describing the translational and rotational symmetry breaking at high and low temperatures respectively. Applications to thermal transport and Nernst effect are considered.