Peak Effect in Twinned Superconductors

Peak effect in twinned superconductors.

Vortex Plastic Motion in Twinned Superconductors.

We present simulations, without electrodynamical assumptions, of Bsx, y, Hstdd, MsHstdd, and JcsHstdd in hard superconductors for a variety of twin-boundary pinning potential parameters, and for a range of values of the density and strength of the pinning sites. We numerically solve the overdamped equations of motion of up to 10 flux-gradient-driven vortices which can be temporarily trapped at ...

Peak Effect in Superconductors: Melting of Larkin Domains

Motivated by the recent observations of the peak effect in high-Tc YBCO superconductors, we reexamine the origin of this unusual phenomenon. We show that the mechanism based on the k-dependence (nonlocality) of the vortex-lattice tilt modulus C44(k) cannot account for the essential feature of the peak effect. We propose a scenario in which the peak effect is related to the melting of Larkin dom...

Negative dynamic creep in the peak-effect regime in type-II superconductors

We report the observation of a negative dynamic creep rate, i.e., increasing irreversibility in the magnetic hysteresis loop for decreasing sweep rate of the magnetic field, in both YBa2Cu3O72d and 2H-NbSe2 single crystals. This phenomenon is found to appear on the increasing branch of the peak effect that corresponds to a state which is intermediate between the dislocation-free Bragg glass and...

Peak effect in the critical current of type II superconductors with strong magnetic vortex pinning.

We perform 2D Langevin simulations studying the peak effect (PE) of the critical current taking into account the temperature dependence of the competing forces. We observe and report that the PE results from the competition of vortex-vortex interactions and vortex-pin interactions which have different temperature dependencies. The simulations reveal that the PE can take place only for certain p...