We investigate the evolution of the interaction of the magnetoplasmon
resonance with the harmonics of the cyclotron resonance as the confinement of
an electron gas in a quantum wire increasingly deviates from the parabolic
case. The occurrence of the Bernstein modes is observed in a time-dependent
Hartree model of a two-dimensional electron gas in a single quantum wire.Comment: 9 pages, 4 figures, uses IOP macros, to appear in the Journal of
Physics: Condensed Matte