Electron trajectories in rectangular antidot superlattices

A periodic array of potential pillars is superimposed on a two-dimensional electron gas being ballistic on the length scale of the lattice period. Pronounced maxima occur in the magnetoresistance of such systems. The magnetoconductivity as obtained from the magnetoresistance via a tensor inversion displays maxima or minima depending on the direction of current flow with respect to the lattice orientation. So-called pinned electron orbits as well as runaway trajectories coexist and specifically influence a given element of the conductivity tensor. In contrast to square lattices, both sets of trajectories show up in the experimental data simultaneously.