Enhanced soft-wall effects for composite fermions in magnetic focusing and commensurability experiments

Abstract

Transverse magnetic focusing in arrays of abutted square cavities and commensurability oscillations in antidot superlattices were investigated around half Landau-level filling in a two-dimensional electron gas. Both experiments support the validity of the composite fermion model and confirm that composite fermions appear to obey quasi-classical dynamics. Nevertheless, compared to electrons, the dynamics of composite fermions in the ballistic transport regime in these etched semiconductor nanostructures is strongly influenced by the inhomogeneous electrostatic potential in the vicinity of the exposed surfaces. Enhanced soft-wall effects emerge in both experiments for the hybrid particles.