Magnetotransport through disordered and anisotropic antidot lattices in GaAs/AlxGa1-xAs heterostructures

We investigate the relation between commensurability oscillations and current flow direction in lateral two-dimensional anisotropic antidot lattices. The anisotropy is introduced as one-directional fluctuation or expansion of the lattice spacing. The fluctuation of the antidot location suppresses the peaks of commensurability oscillations. The suppression is dominated by the fluctuations perpendicular to the current flow direction. In one-directional expanded lattices, the peaks appear at the magnetic fields which correspond to the cyclotron motions with the diameter of the periods perpendicular to the current. These results suggest that the commensurability oscillations are determined only by the period along the direction perpendicular to the current.