Calculation of one-dimensional hot-electron mobility in GaAs quantum wires at microwave and millimeterwave frequencies

Abstract

Small-signal microwave and millimeterwave mobilities of degenerate hot electrons moving one-dimensionally in a GaAs quantum wire are calculated for lattice temperatures of 77 K and 300 K. Carrier scattering by longitudinal optic phonons via polar coupling, acoustic phonons via deformation potential coupling, and ionized impurities is included. The AC mobility is found to remain fairly constant up to about 100 GHz, but the drift velocity begins to lag behind the applied field above about 1- GHz. An increase of the channel width or the carrier concentration enhances both the magnitude and the phase lag of the AC mobility. The 3-dB cutoff frequency increases with decreasing channel width and increasing bias field. It is higher for 300 K than for 77 K.