%0 Book Section %1 statphys23_0399 %A Moretti, P. %A Miguel, M.C. %A Zaiser, M. %A Zapperi, S. %B Abstract Book of the XXIII IUPAP International Conference on Statistical Physics %C Genova, Italy %D 2007 %E Pietronero, Luciano %E Loreto, Vittorio %E Zapperi, Stefano %K dislocation disorder lattice plasticity statphys23 topic-7 transport vortex %T Statistical properties of plasticity and transport in vortex lattices %U http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=399 %X We investigate the effects that plasticity of vortex lattices has on current transport in disordered Type II superconductors. Vortex lattices are often encountered in a polycrystalline metastable state, where topological defects such as dislocations arrange into large grain boundaries, due to their long-range interactions (1). Applied currents plastically deform the lattice, mainly inducing collective motion of dislocation assemblies through a disordered landscape. We propose a statistical analysis of the dynamics of disordered vortex polycrystals in the framework of collective transport theories (2). We analytically derive equilibrium properties of vortex lattice grain boundaries in the limits of low and high defect densities and study their collective behaviour around the depinning transition. Grain boundaries prove to be stiffer than isolated dislocations and the grain structure appears less prone to deformation, adjusting more effectively to the disordered environment. This is expected to induce dramatic changes in current transport properties of the underlying superconductor. We perform a numerical analysis in order to substantiate this global picture. In our simulations, the grain structure produces critical current enhancement and I-V curve hysteresis. Such phenomena are commonly observed in field-cooling experiments and are a typical fingerprint of a metastable state, in which the recovery of crystalline order is hindered by quenched disorder. We aim to corroborate the proposed picture by investigating the role of relevant variables such as magnetic field, pinning strength and defect density. .5cm (1) P. Moretti, M.-C. Miguel, M. Zaiser and S. Zapperi, Growth of a vortex polycrystal in type II superconductors, Phys. Rev. Lett. 92, 257004 (2004), cond-mat/0312382. (2) P. Moretti, M.-C. Miguel and S. Zapperi, Grain boundaries in vortex matter, Phys. Rev. B 72, 014505 (2005), cond-mat/0412437.

@incollection{statphys23_0399, abstract = {We investigate the effects that plasticity of vortex lattices has on current transport in disordered Type II superconductors. Vortex lattices are often encountered in a polycrystalline metastable state, where topological defects such as dislocations arrange into large grain boundaries, due to their long-range interactions (1). Applied currents plastically deform the lattice, mainly inducing collective motion of dislocation assemblies through a disordered landscape. We propose a statistical analysis of the dynamics of disordered vortex polycrystals in the framework of collective transport theories (2). We analytically derive equilibrium properties of vortex lattice grain boundaries in the limits of low and high defect densities and study their collective behaviour around the depinning transition. Grain boundaries prove to be stiffer than isolated dislocations and the grain structure appears less prone to deformation, adjusting more effectively to the disordered environment. This is expected to induce dramatic changes in current transport properties of the underlying superconductor. We perform a numerical analysis in order to substantiate this global picture. In our simulations, the grain structure produces critical current enhancement and I-V curve hysteresis. Such phenomena are commonly observed in field-cooling experiments and are a typical fingerprint of a metastable state, in which the recovery of crystalline order is hindered by quenched disorder. We aim to corroborate the proposed picture by investigating the role of relevant variables such as magnetic field, pinning strength and defect density. \vspace{.5cm} (1) P. Moretti, M.-C. Miguel, M. Zaiser and S. Zapperi, {\it Growth of a vortex polycrystal in type II superconductors}, Phys. Rev. Lett. 92, 257004 (2004), cond-mat/0312382. (2) P. Moretti, M.-C. Miguel and S. Zapperi, {\it Grain boundaries in vortex matter}, Phys. Rev. B 72, 014505 (2005), cond-mat/0412437.}, added-at = {2007-06-20T10:16:09.000+0200}, address = {Genova, Italy}, author = {Moretti, P. and Miguel, M.C. and Zaiser, M. and Zapperi, S.}, biburl = {https://www.bibsonomy.org/bibtex/273ad6a2d71ccb8b4bf68425515406ac1/statphys23}, booktitle = {Abstract Book of the XXIII IUPAP International Conference on Statistical Physics}, editor = {Pietronero, Luciano and Loreto, Vittorio and Zapperi, Stefano}, interhash = {7a0b9c51c52d77dadb385e780fba95e6}, intrahash = {73ad6a2d71ccb8b4bf68425515406ac1}, keywords = {dislocation disorder lattice plasticity statphys23 topic-7 transport vortex}, month = {9-13 July}, timestamp = {2007-06-20T10:16:19.000+0200}, title = {Statistical properties of plasticity and transport in vortex lattices}, url = {http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=399}, year = 2007 }