Measurements of a composite fermion split-gate
Journal
Surface Science
Journal Volume
361-362
Pages
71-74
Date Issued
1996
Author(s)
Abstract
Recent theoretical and experimental work demonstrates that at filling factor ν = 1/2, a two-dimensional electron gas can be described in terms of composite fermions (CFs), for which the effective magnetic field vanishes. We present low-temperature measurements on a wide split-gate (SG) device investigating CFs in the quantum point contact (QPC) defined by such a structure. Negative magnetoresistance due to suppression of backscattering in the QPC was observed both around zero magnetic field and ν = 1/2. We have also measured the resistance of a CF QPC at zero effective magnetic field as a function of gate voltage, with a compensating field to maintain ν = 1/2 in the QPC. Using a simple model, we have determined the channel widths for CFs, which are narrower than those for electrons.
SDGs
Type
journal article