MAGNETOPLASMONS IN A QUASI-ONE-DIMENSIONAL QUANTUM-WIRE

Plasmon spectra in a quasi-1D quantum wire under a transverse magnetic field are calculated within the random phase approximation (RPA) in t he long-wavelength limit. We find interesting collective behaviours co rresponding to the edge state electrons in both intrasubband and inter subband (between occupied subbands) excitations. The various plasmon m odes show anomalous magnetic field dependences. The intrasubband and s ome segments of the intersubband excitation frequencies decrease with increasing field. These results are in good agreement with experiment.