Vv. Dotsenko et al., ATTENUATION OF PHONON-RIPPLON OSCILLATIONS IN AN ELECTRON CRYSTAL OVER SUPERFLUID HE-3-HE-4 SOLUTIONS, Low temperature physics, 23(9), 1997, pp. 772-774
The phonon-ripplon oscillation spectrum of a Wigner crystal with a sur
face density 1.3 . 10(9) cm(-2) of electrons over superfluid He-4 and
He-3-He-4 solutions is studied in the temperature range 70-600 mK. Mea
surements were made in the frequency range 1-20 MHz. It is shown that
resonance frequencies are in good agreement with the theoretical estim
ates. An analysis of the data shows that the attenuation of capillary
waves is not the main mechanism determining the energy losses in a Wig
ner crystal. A new technique employing the width of the coupled phonon
-ripplon resonances is used to determine the mobility of Wigner crysta
ls. (C) 1997 American Institute of Physics.