Simulation Study Of The Mixed-State In Inhomogeneous Superconductors

A simulation study of the mixed state in inhomogeneous type-II superconductors is given based on the time-dependent Ginzburg-Landau equation. Defects are introduced by spatially changing the parameters in the Ginzburg-Landau free energy. It is shown how the magnetic flux is pinned by various defects and how the flux lattice is distorted by pinning due to defects. The distribution of the vortex density trapped in the twin boundaries is examined and compared with experimental results observed in high-temperature superconductors by the high-resolution Bitter technique.