Phase-coherent electrons in a finite antidot lattice

Abstract

Antidot lattices with a finite number of periods are fabricated such that the size of the total system is smaller than the phase-coherence length of the electrons at low temperatures. The magnetoresistance is dominated by reproducible quantum fluctuations as well as by classical commensurability oscillations. We attribute these fluctuations to electrons 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 and related to the existence of classically pinned electron orbits.