TEMPERATURE-DEPENDENCE OF PROPAGATION AND DAMPING OF NONRESONANT EDGEMAGNETOPLASMONS FOR ELECTRONS ON LIQUID-HELIUM

Very low frequency edge magnetoplasmons (EMP's) for electrons on liqui d helium are investigated in the nonresonant regime from current-volta ge phase shift measurements for temperatures of 1.57 K and 1.93 K. At these temperatures the mobilities, and therefore the zero field phase shifts, differ by about a factor of three. The phase shift in the EMP regime is the same within 10%. This confirms the theoretically predict ed temperature independence of the EMP dispersion.