A new low frequency propagating mode in a 2DEG in a magnetic field

The electrical admittance of a two-dimensional electron gas, density n, on liquid helium is found to oscillate with magnetic field B at audio frequencies ohms in the low frequency regime ohmsτ ≪ 1, where τ is the relaxation time. This is interpreted as evidence for an edge magnetoplasmon with a propagation constant k ∞ ohmsB/n. Below 1 K, resonant behaviour is observed.