We investigated vortex dynamics in a pristine sample of type II superconductor NbSe2 by scanning tunneling microscopy at 4.2 K. The decay of the magnetic field at ∼ nT/s in our superconducting magnet induced the motion of vortices at ∼ pm/s. Characteristics of the trajectories and speed variations of the moving vortices clearly revealed the potential landscape of vortices in the sample. Our vor...

We study a functional field theory of membranes coupled to a rank–three tensor gauge potential. We show that gauge field radiative corrections lead to membrane condensation which turns the gauge field into a massive spin–0 field. This is the Coleman–Weinberg mechanism for membranes. An analogy is also drawn with a type–II superconductor. The ground state of the system consists of a two–phase me...

We study a model of interacting vortices in a type II superconductor. In the weak coupling limit, we constructed a mean-field theory which allows us to accurately calculate the vortex density distribution inside a confining potential. In the strong coupling limit, the correlations between the particles become important and the mean-field theory fails. Contrary to recent suggestions, this does n...

We consider, via numerical calculations, a hybrid structure made of a semimagnetic Cd1−xMnxTe quantum well deposited in a close proximity to superconducting niobium film. We simulate photoluminescence and the Faraday rotation spectra, modified by the presence of vortices in this type II superconductor. The magnitude of the evaluated effects is small — the vortex induced spectral line shape vari...

We consider the formation of defects in a nonequilibrium second-order phase transition induced by an instantaneous quench to zero temperature in a type II superconductor. We perform a full nonlinear simulation where we follow the evolution in time of the local order parameter field. We determine how far into the phase transition theoretical estimates of the defect density based on the Gaussian ...

We report transverse-field and zero-field muon spin rotation and relaxation studies of the superconducting rhenium oxide pyrochlore, Cd2Re2O7. Transverse-field measurements (H=0.007 T) show line broadening below T(c), which is characteristic of a vortex state, demonstrating conclusively the type-II nature of this superconductor. The penetration depth is seen to level off below about 400 mK (T/T...

We study the pinning dynamics of magnetic flux (vortex) lines in a disordered type-II superconductor. Using numerical simulations of a directed elastic line model, we extract the pinning time distributions of vortex line segments. We compare different model implementations for the disorder in the surrounding medium: discrete, localized pinning potential wells that are either attractive and repu...

We describe results of Monte Carlo simulations on a model that seems to have the necessary ingredients to describe a disordered type-II superconductor in a magnetic field. We compute the free energy cost to twist the direction of the phase of the condensate and analyze the results by finite-size scaling. The results show convincingly that the model has different behavior as a function of dimens...