Collective excitations in double quantum wells with strong tunnel coupling

Spectra of collective and magnetic excitations in symmetric double quantum wells with strong tunnel coupling were studied by inelastic scattering. Gaps in the spectrum of collective and single-particle excitations associated with tunnel interwell splitting were measured. New excitation modes, namely, tunnel Bernstein modes, were detected in a magnetic field. Based on the dispersion and magnetic-field dependences of the energies of inelastic light scattering lines, a classification of excitations and magnetic excitations was given.