Observation of audio-frequency edge magnetoplasmons in the classical two-dimensional electron gas

The electric admittance of a two-dimensional electron gas on liquid helium measured at audio frequencies ¿ is observed to oscillate as a function of magnetic field at strong magnetic fields. The oscillations can be attributed to the propagation of very-low-frequency (¿t~10-6, t scattering time; ¿/¿c~10-8, ¿c cyclotron frequency) edge magnetoplasmons. The directly determined dispersion relation agrees with theory and quantitatively with measurements in the collisionless regime (¿t»1). The attenuation, theoretically obtained by incorporating the screening in a simple local-capacitance model, agrees well with experiments

Numerical calculations on edge magnetoplasmons for electrons on helium with inhomogeneous density and capacitance profiles

The transmission line model to describe the AC-response of electrons on helium in a magnetic field has been extended by introducing inhomogeneous electron density and capacitance profiles at the edge. The transmission line equations were solved numerically for mobility values corresponding to t=1.8 K. The results yield an oscillatory response as a function of magnetic field, in agreement with experimental observations and are attributed to damped edge magnetoplasmons (EMP's)

Hall effect induced phase shifts in a capacitively coupled two-dimensional electron gas

The influence of the Hall effect on current-voltage phase shift measurements is reported for the capacitively coupled two-dimensional electron gas on liquid helium. The frequencies are low enough that phase shifts due to edge mode propagation are negligible. The Hall effect typically leads to a decreasing phase shift with increasing magnetic field, as a result of the tendency to make the entire edge of the electron sheet an equipotential- (and equiphase) line

The Hall effect in a classical two-dimensional electron gas without electrical contacts

Measurements of the phase shift between current and voltage as a function of magnetic field are reported for electrodes in an array which are capacitively coupled to the two-dimensional electron gas on liquid helium. It is experimentally shown that the phase of the current at the extreme edge of the sample decreases with magnetic field when the Hall angle comes close to 90 degrees . It is shown that this is a direct consequence of the unusual condition of total charge conservation for an electrically isolated sample

The AC Hall effect for electrons on liquid helium in ultra-high magnetic fields

Current-voltage phase shift measurements are reported between electrodes situated near the rim of an array located below a charged liquid helium surface. Data are taken in magnetic fields up to 20 T at a temperature near 2 K. Under these conditions, the ultra-quantum limit is reached, where the Landau level width is larger than the electron thermal energy. Interpreting the data in terms of the AC Hall effect, or edge magnetoplasmon, suggests that the Hall resistivity deviates from its classical value for fields greater than 10 T