Magnetoconductance Oscillations Linear in ΔB In Semiconductor Surface Superlattices

Abstract

In the past decade, a number of experiments performed in thin metal and semiconductor films have demonstrated the possibility of observing quantum interference of electrons within condensed matter. Particularly convincing demonstrations have come from experiments in multiply-connected structures, for which the Aharonov-Bohm effect can be observed in magnetoresistance measurements of doubly-connected, one-dimensional rings whose characteristic lengths are shorter than the inelastic mean free path, or the diffusion length, of the electrons in metals (Webb et al., 1985; Chandrasekhar et al., 1985; Washburn and Webb, 1985) and semiconductors (Timp et al., 1987a; Ford et al., 1988; Ishibashi et al., 1987b; Mankiewich et al., 1988). Here, oscillations in the magnetoresistance are observed that arise from phase interference among topologically inequivalent paths (e.g. around opposite arms of a ring). The large majority of experiments demonstrating these effects have involved topologies with one or a relatively small number of individual rings (Umbach et al., 1986).