Fizika Nizkikh Temperatur: Volume 25, Number 8-9 (August 1999), p. 876-888 ( to contents , go back )
Coupling of electromagnetic and sound modes in metals
L. T. Tsymbal, A. N. Cherkasov, and O. F. Panchenko
A. Galkin Institute for Physics and Engineering of National Academy of Sciences of Ukraine,R. Ljuksemburg 72, 340114 Donetsk, Ukraine
(Received March 3, 1999)
Comprehensive theoretical data on coupling of weakly damped electromagnetic and sound waves in metals are presented. It is found that the behaviors of coupling of modes which propagate in the same (helicon-phonon resonance) or opposite (doppleron-phonon resonance) directions are fundamentally different. In the first case the dispersion curves are splitted but in the second case they are bound. As a result in the collisionless limit there occurs a gap in the spectra of the coupled modes and the both modes are sound-like. It is shown that in the case of doppleron-phonon resonance both induction and deformation interactions of the electrons with the lattice should be taken into account.