QUENCHED AND NEGATIVE HALL-EFFECT IN PERIODIC MEDIA - APPLICATION TO ANTIDOT SUPERLATTICES

We find the counterintuitive result that electrons move in opposite di rection to the free-electron (E X B)-drift when subject to a two-dimen sional periodic potential. We show that this phenomenon arises from ch aotic channeling trajectories and by a subtle mechanism leads to a neg ative value of the Hall resistivity for small magnetic fields. The eff ect is present also in experimentally recorded Hall curves in antidot arrays on semiconductor heterojunctions but so far has remained unexpl ained.