Critical scaling and aging near the flux-line-depinning transition

Abstract

We utilize Langevin molecular dynamics simulations to study dynamical critical behavior of magnetic flux lines near the depinning transition in type-II superconductors subject to randomly distributed attractive point defects. We employ a coarse-grained elastic line Hamiltonian for the mutually repulsive vortices and purely relaxational kinetics. In order to infer the stationary-state critical exponents for the continuous non-equilibrium depinning transition at zero temperature T = 0 and at the critical driving current density jc, we explore two-parameter scaling laws for the flux lines' gyration radius and mean velocity as functions of the two relevant scaling fields T and j − jc. We also investigate critical aging scaling for the two-time height auto-correlation function in the early-time non-equilibrium relaxation regime to independently measure critical exponents. We provide numerical exponent values for the distinct universality classes of non-interacting and repulsive vortices.

Pinning-depinning transitions in two classes of discrete elastic-string models in (2+1)-dimensions

“…These differences can be attributed to stronger synergies between interface elements resulting from longer-range correlation. Considering equation (17), we know that a larger θ means that the interface saturation velocity of a long-range system is more sensitive to changes in external forces. These rules are also applicable to the comparison between QKPZ and QEW.…”

“…In recent decades, much attention has been attached to the pinning-depinning transition of a driven interface in quenched random media [1][2][3][4][5][6][7][8][9][10][11][12], which has served for interpretation of many other physical phenomena such as immiscible displacements of fluids in porous media [13], field-driven motion of domain walls in magnetic systems [14], vortices and flux lines in superconductors [3,4,[15][16][17][18][19][20].…”

Pinning-depinning transitions in two classes of discrete elastic-string models in (2+1)-dimensions

“…In recent decades, much attention has been attached to the pinning-depinning transition of a driven interface in quenched random media [1][2][3][4][5][6][7][8][9], which has served for interpretation of many other physical phenomena such as immiscible displacements of fluids in porous media [10], field-driven motion of domain walls in magnetic systems [11], vortices and flux lines in superconductors [3,4,[12][13][14][15][16][17].…”