Electron-phonon interaction in the transport properties of quantum wires

Abstract

The conductance of a 20 am long quantum wire in an AlGaAs/GaAs heterostructure is investigated as a function of a perpendicular magnetic field and the temperature. Quantization in units of 2e2 /h occurs at moderate field strengths and sufficiently low temperatures. For higher magnetic fields an additional conductance plateau at e2 /h occurs due to an exchange- interaction-induced Zeeman splitting of the corresponding subband. With increasing temperature, the conductance plateaus are partially reduced, which is characteristic for the interaction between the electrons and three-dimensional phonons. The interpretation is based on an enhancement of the electron-phonon scattering as soon as the Fermi velocity within a subband exceeds the sound velocity. Within the region of strong scattering the temperature dependence of the conductance changes from Ts to T. © 1995 IOP Publishing Ltd.