A. Chavezpirson et al., RAPID RELAXATION OF HOT CARRIERS IN GAAS FRACTIONAL-LAYER SUPERLATTICE QUANTUM WIRES, Applied physics letters, 69(2), 1996, pp. 218-220
We measure the hot carrier relaxation in two GaAs quantum wire arrays
made from fractional-layer superlattices (FLS). Using femtosecond opti
cal pump-probe spectroscopy, we measure the differential transmission
spectra for various pump-probe time delays from which we determine the
carrier thermalization times. Although the two FLS structures have di
fferent degrees of one-dimensional confinement at the band edge, we ob
serve rapid (<2 ps) and efficient carrier relaxation in both cases wit
h no sign of the inhibited relaxation predicted for ideal one-dimensio
nal structures. We believe that FLS quantum wife structures avoid rela
xation bottlenecks because the shape of the FLS confinement potential
produces high energy states which are two dimensional in character and
which facilitate rapid energy relaxation. (C) 1996 American Institute
of Physics.