Dynamics of disordered vortex matter in type II superconductors

Abstract

Dynamics of homogeneous moving vortex matter is considered beyond the linear response. The framework is the time dependent Ginzburg - Landau equation within the lowest Landau level approximation. Both disorder and thermal fluctuations are included using the Martin-Siggia-Rose formalism. We determine the critical current as function of magnetic field and temperature Jc(B,T). The surface in the J-B-T space defined by the function separates between the dissipative moving vortex matter regime(flux flow)and an amorphous vortex "glass". Both the thermal depinning and the depinning by a driving force are taken into account. The static irreversibility line, determined by Jc(B,T)=0 is compared to experiments in layered HTSC, and is consistent with the one obtained using the replica approach. The non-Ohmic I-V curve (in the depinned phase) is obtained and compared with experiment in layered superconductors and thin films.