Josephson vortices and solitons inside pancake vortex lattice in layered superconductors

摘要

In very anisotropic layered superconductors a tilted magnetic field generatescrossing vortex lattices of pancake and Josephson vortices (JVs). We study theproperties of an isolated JV in the lattice of pancake vortices. JV inducesdeformations in the pancake vortex crystal, which, in turn, substantiallymodify the JV structure. The phase field of the JV is composed of two types ofphase deformations: the regular phase and vortex phase. The phase deformationswith smaller stiffness dominate. The contribution from the vortex phasesmoothly takes over with increasing magnetic field. We find that the structureof the cores experiences a smooth yet qualitative evolution with decrease ofthe anisotropy. At large anisotropies pancakes have only small deformationswith respect to position of the ideal crystal while at smaller anisotropies thepancake stacks in the central row smoothly transfer between the neighboringlattice positions forming a solitonlike structure. We also find that even athigh anisotropies pancake vortices strongly pin JVs and strongly increase theirviscous friction.