Measurements of a composite fermion split-gate device
Journal
Physical Review B - Condensed Matter and Materials Physics
Journal Volume
53
Journal Issue
12
Date Issued
1996
Author(s)
Abstract
Recent theoretical and experimental work demonstrates that a two-dimensional electron gas at Landau-level filling factor (Formula presented) can be described in terms of composite fermions (CFșs) for which the effective magnetic field (Formula presented) vanishes. We have measured the transport properties of CFșs in a quantum point contact (QPC) defined by a wide split-gate device. Negative magnetoresistance due to suppression of backscattering in the QPC was observed both around zero magnetic field (Formula presented) and (Formula presented). We have also measured the resistance of a composite fermion QPC at (Formula presented) as a function of gate voltage, with an applied magnetic field to maintain (Formula presented) in the QPC. Using a simple model to compare the results for (Formula presented) and (Formula presented), we have determined that the channel widths for CFșs are narrower than those for electrons. © 1996 The American Physical Society.
SDGs
Type
journal article