Growth of a tensionless interface in anisotropic random media.

We introduce a simple growth model where a tensionless interface grows in random media. In this model, the degree of anisotropy of the random media is controlled by a variable g. When g=0, there is no anisotropic property of the random media. But, the anisotropic property increases as g does from 0. From the numerical simulations, we find that this model belongs to the quenched Herring-Mullins universality class when g=0. Interestingly, however, we find that this model belongs to the quenched Kardar-Parisi-Zhang universality class when g is nonzero.