PHASE-COHERENT ELECTRONS IN A FINITE ANTIDOT LATTICE

Antidot lattices with a finite number of periods are fabricated such t hat the size of the total system is smaller than the phase-coherence l ength of the electrons at low temperatures. The magnetoresisance is do minated by reproducible quantum fluctuations as well as by classical c ommensurability oscillations. We attribute these fluctuations to elect rons that travel phase coherently over the entire system and interfere with each other under the influence of the geometry of the potential landscape. The presence of Aharonov-Bohm oscillations is identified an d related to the existence of classically pinned electron orbits.