The three-dimensional uniformly frustrated XY model is simulated to search for a predicted ‘‘vortex loop’’ transition within the vortex line liquid phase of a strongly type-II superconductor in an applied magnetic field. Results are shown to strongly depend on the precise scheme used to trace out vortex line paths. While we find evidence for a transverse vortex path percolation transition, no s...

When vortices move in a type-II superconductor under the action of an electric current, they interact with the crystal lattice generating acoustic waves. This results in a radiation-friction component to the vortex dissipation, which peaks at values of vortex velocity where there are phonons in the Brillouin zone of the crystal with matching phase and group velocities ~the van Hove condition!. ...

We propose a simple method by which we can explain the magnetic-field dependence of the longitudinal ultrasonic attenuation in a type-II superconductor. It gives a curve which is in good agreement with experimental data, in paticular, near the lower critical field Hc1. We compare it with conventional methods, which is not in good agreement with the experimental data near Hc1 but near the upper ...

A serious obstacle impeding the application of lowand hightemperature superconductor devices is the presence of trapped magnetic flux: flux lines or vortices can be induced by fields as small as the Earth’s magnetic field. Once present, vortices dissipate energy and generate internal noise, limiting the operation of numerous superconducting devices. Methods used to overcome this difficulty incl...

In a uniform flux-flow state of a type-II superconductor, (i) the resistivity tensor p,~ is independent of the dissipative transport current density J, and (ii) there exists a constraint on the relative orientation of J and the average Aux density B. These two simple general properties can already account for the Lorentz-force independence of the resistive transition in high-T superconductors f...

We outline the universal and finite temperature critical properties of the 3D-XY model, extended to anisotropic extreme type-II superconductors, as well as the universal quantum critical properties in 2D. On this basis we review: (i) the mounting evidence for 3D-XY behavior in optimally doped cuprate superconductors and the 3D to 2D crossover in the underdoped regime; (ii) the finite size limit...

We calculate the transition line of the first-order melting of vortex lattice in a three-dimensional type-II superconductor in fields of several Tesla, using the results from the density-functional theory of vortex melting in two-dimensions and a self-consistent Hartree treatment of correlations along the field. The result is in quantitative agreement with experiment. The temperature width of t...