Depinning of KPZ Interfaces in Fractional Brownian Landscapes

Abstract

We explore the critical dynamics of driven interfaces propagating through a two dimensional disordered medium with long range spatial correlations, modeled using fractional Brownian motion. Departing from conventional models with uncorrelated disorder, we introduce quenched noise fields characterized by a tunable Hurst exponent H, allowing systematic control over the spatial structure of the background medium. The interface evolution is governed by a quenched Kardar Parisi Zhang equation modified to account for correlated disorder, namely QKPZ. Through analytical scaling analysis, we uncover how the presence of long-range correlations reshapes the depinning transition, alters the critical force Fc, and gives rise to a family of critical exponents that depend continuously on H. Our findings reveal a rich interplay between disorder correlations and the non-linearity term in QKPZ, leading to a breakdown of conventional universality and the emergence of nontrivial scaling behaviors. The exponents are found to change by H in the anticorrelation regime, while they are nearly constant in the correlation regime, suggesting a super-universal behavior for the latter. By a comparison with the quenched Edwards Wilkinson model, we study the effect of the non linearity term in the QKPZ model. This work provides new insights into the physics of driven systems in complex environments and paves the way for understanding transport in correlated disordered media.