Depinning of an anisotropic interface in random media: The tilt effect

Abstract

We study the tilt dependence of the pinning-depinning transition for an interface described by the anisotropic quenched Kardar-Parisi-Zhang equation in 2+1 dimensions, where the two signs of the nonlinear terms are different from each other. When the substrate is tilted by m along the positive sign direction, the critical force F(c)(m) depends on m as F(c)(m) - F(c)(0) similar to - \m\(1.9(1)). The interface velocity v near the critical force follows the scaring form v similar to \f\ (theta)Psi (+/-)(m(2) / \f\ (theta +phi)) with theta = 0.9(1) and phi = 0.2(1), where f = F - F(c)(0) and F is the driving force.