Magnetooscillations of temperature and microwave absorption in a highly correlated 2D electron gas on liquid helium

The Coulombic effect on microwave-induced electron heating in a 2D electron gas on liquid helium under quantizing magnetic field is theoretically studied. An extension of the linewidth of the intersubband resonance which takes into account squeezing of the electron density of states into Landau levels and strong internal electric fields of fluctuational origin is proposed. This approximation results in two-hump peaks of electron temperature and power absorption near certain values of the magnetic field. For low electron densities, the asymmetry of the two-hump peaks of power absorption is shown to be opposite to the asymmetry of electron temperature peaks, which explains experimental observations. The importance of two-ripplon emission processes for the description of subband occupancies and the energy relaxation rate was demonstrated. (author)