Numerical studies of superfluids and superconductors

摘要: In this thesis we demonstrate the power of Gross-Pitaevskii and time-dependent Ginzburg-Landau equations by numerically solving them for various fundamental problems related to superfluidity superconductivity. We start studying motion a massive object through quantum fluid modelled equation. Below critical velocity, does not exchange momentum or energy with fluid. This is manifestation its superfluid nature. discuss effect applying constant force show that small forces vortex ring created which becomes attached. For larger detaches from observe periodic shedding rings. All transfered system contained within rings drag on due recoil emission. If exceed speed sound, there an additional contribution sound To make link superconductivity, then states in rotating system. ground state, regular arrays vortices are observed which, systems containing many vortices, mimic solid-body rotation. second part thesis, initially review solutions applied magnetic field. superconducting disks similar those superfluids. Finally, study electrical current flow along wire subject external flux lines, hence dissipation, Lorentz force. measure V – I curve analogous superfluid. With introduction impurities, lines become pinned gives rise increased current.