Published in Physical Review B, Volume 70, Issue 2, July 14, 2004, pages 024205.1-024205.29.
Copyright © 2004 American Physical Society. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Physical Society. The following article appeared in Physical Review B and may be found at http://dx.doi.org/10.1103/PhysRevB.70.024205.
NOTE: At the time of publication, the author Karl Saunders was not yet affiliated with Cal Poly.
The driven transport of plastic systems in various disordered backgrounds is studied within mean field theory. Plasticity is modeled using nonconvex interparticle potentials that allow for phase slips. This theory most naturally describes sliding charge density waves; other applications include flow of colloidal particles or driven magnetic flux vortices in disordered backgrounds. The phase diagrams exhibit generic phases and phase boundaries, though the shapes of the phase boundaries depend on the shape of the disorder potential. The phases are distinguished by their velocity and coherence: the moving phase generically has finite coherence, while pinned states can be coherent or incoherent. The coherent and incoherent static phases can coexist in parameter space, in contrast with previous results for exactly sinusoidal pinning potentials. Transitions between the moving and static states can also be hysteretic. The depinning transition from the static to sliding states can be determined analytically, while the repinning transition from the moving to the pinned phases is computed by direct simulation.