Investigation of microwave absorption of surface-state electrons on liquid ³He

We report on the experimental study of the resonance microwave absorption of surface-state electrons (SSE) on liquid ³He. The absorption is detected as a variation of the microwave power passing through the experimental cell, or as a resonance-induced change in the electron conductivity. In the latter method a decrease of the conductivity is observed, which points out on the possibility of substantial heating of the electrons by the absorbed microwave power. In a vapor-atom scattering regime the temperature dependence of the linewidth agrees well with the theoretical model, and the absolute value of the measured linewidth is about twice larger than the theoretical one. At very high microwave power the side band absorption peaks are observed.