Edge magnetoplasmon (EMP) transport in gated and ungated quantum Hall systems is investigated by time-of-flight measurements. We measured the velocity, the amplitude, and the broadening of the EMP pulse injected by applying a voltage pulse to an Ohmic contact. We show that the transverse width of EMPs in the ungated sample is determined by the potential profile in the edge region, independent of the filling factor. In the gated sample, on the other hand, EMPs are confined by the innermost incompressible strip and their transverse width depends on the filling factor and the bulk electron density. We also find that scattering of EMPs by the bulk electrons is modified by the presence of the gate.

• Received 15 February 2011

DOI:https://doi.org/10.1103/PhysRevB.84.045314