TEMPERATURE-DEPENDENT MAGNETOTRANSPORT PROPERTIES FOR SYSTEMS OF FEW QUANTUM WIRES

We have investigated temperature-dependent magnetotransport properties of quantum wires fabricated on high mobility GaAs-GaAlAs modulation d oped heterostructures. Laser holography and optical lithography were u sed to define multiple quantum wire systems with 30 wires in parallel. These ''few wire systems'' turn out to have the best signal to noise ratio for systematic magnetic depopulation and magnetophonon resonance measurements. In the examined temperature range between 1.9 and 160 K it was found that the 1D subband energies increase strongly with decr easing 1D electron density and the polaron mass increases with increas ing 1D subband spacing. Between 100 and 160 K, magnetophonon resonance data indicate a decline of both the subband spacing and also the pola ron mass with increasing temperature. This effect is most probably due to an increase of the electron concentration with increasing temperat ure.