A two-dimensional electron crystal over liquid helium in the nonlinear mode. An analysis of resonance spectra of the electron-ripplon oscillations
V.E. Syvokon and I.V. Sharapova
B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Nauky Ave., Kharkiv 61103, Ukrain
Received October 20, 2017
The spectrum of coupled electron-ripplon oscillations in the Wigner crystal is studied experimentally, depending on amplitude of the exciting signal. In-creasing the exciting voltage is found to cause the noticeable spectrum distortion and the shift of the resonances down to lower frequencies. Excitation of the non-axisymmetrical oscillations is found under of the spectra analysis. Because of radial symmetry of the cell and the exciting electrode a possible reason for such excitations may be the crystal lattice distortion. It is suggested under analysis that the electron-ripplon interaction contributes only in the electron effective mass renormalization.
PACS: 73.40.–c Electronic transport in interface structures;
Key words: Wigner crystal, liquid helium, two-dimensional system, resonance spectra, electron-ripplon oscillations.
Published online: February 26, 2018