Edge magnetoplasma excitations in quantum wire arrays

Abstract

We report the low-temperature microwave properties of edge magneto-plasma excitations in quantum-wire arrays, fabricated from a two-dimensional electron gas in a GaAs/AlGaAs heterostructure and embedded in the slots of a 50-Omega meandering coplanar waveguide. The plot of frequency versus Landau level filling factors with strong absorption gives a series of barn-shaped curves with tops being centered in the quantum Hall effect plateaus and following a straight line through the origin. Away from the plateau center, the absorption dip becomes weaker and disappears near the plateau-plateau transition regime, qualitatively following the magneto hydrodynamic model. At frequencies above this barn-shaped part, however, we also observed unexpected resonant dips. (c) 2007 Published by Elsevier B.V.