Bernstein modes in quantum wires and dots

The excitation of magnetoplasmons in ${\mathrm{Al}}_{\mathit{x}}$ ${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As-GaAs quantum dots and wires with far-infrared transmission spectroscopy is investigated. An interaction of the magnetoplasmon resonance with harmonics of the cyclotron resonance n${\mathrm{\omega }}_{\mathit{c}}$ (n=2,3) is observed. Results of self-consistent calculations of the magnetoplasmon dispersion show similar effects when the lateral confinement of the electrons has a slight deviation from a parabolic form. Comparison of the results indicates a good qualitative agreement between experiments and models.