Acoustic magnetoplasma excitations in double electron layers

The inelastic light scattering technique is used to study the spectra of intraband excitations of the quasi-two-dimensional electron system in GaAS/AlGaAs double quantum wells. A new collective mode, namely, the acoustic plasmon, is discovered and investigated. The dispersion law of the acoustic mode and its dependence on the electron density are measured. It is shown that, in a perpendicular magnetic field, a hybridization of the acoustic plasmon with the cyclotron mode takes place. The properties of the hybrid acoustic magnetoplasma collective excitations are studied.