2-DIMENSIONAL ELECTRONS IN A MAGNETIC SUPERLATTICE

We report on the motion of two-dimensional electrons in a magnetic fie ld which is periodic on the scale of a few hundred nanometres. Such a system exhibits novel magnetoresistance oscillations that we unambiguo usly identify as due to a commensurability effect between the period o f the magnetic field and the diameter of the cyclotron orbit. We find that a semiclassical picture of electron motion can quantitatively des cribe all of the observed experimental features. We also propose metho ds of optimizing the effects of the magnetic modulation in hybrid semi conductor-superconductor devices.