Effective-medium approximation with asymmetric transition rates

BUSTINGORRY SEBASTIAN; CÁCERES MANUEL O; REYES EDUARDO R

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

American Physical Society

Lugar: New York; Año: 2002 vol. 65 p. 165205 - 165212

0163-1829

An effective-medium approximation considering asymmetric transition rates is presented for a D-dimensional anisotropic random walk. Our approach allows to obtain a set of 2D frequency-dependent effective transition rates in a self-consistent way. Even when these coupled equations could look unwielding, we have been able to work out some particular cases, i.e., using a separablelike ansatz the asymmetric effective-medium approximation is shown to be reduced, under a transformation of variables, to the study of the symmetric case. Within this basic formalism, a biased diffusion problem in an anisotropic two-dimensional percolation model is analyzed. The asymmetric effective-medium approximation is finally compared against Monte Carlo simulations, and a good agreement is found for small bias values.