|
Abstract |
Nonlinear Surface Acoustic Wave
Interaction with Two-Dimensional Electronic System
A.M.Diakonov, I.L.Drichko, V.D.Kagan,
T.A.Polyanskaya, I.Yu.Smirnov (Ioffe Physico-Technical Institute RAS,
St.Petersburg, Russia); A.I.Toropov (Semiconductors Physics Institute SD of
RAS, Novosibirsk, Russia.)
e-mail:
Andrey.M.Diakonov@pop.ioffe.rssi.ru
Attenuation
and sound velocity changes of a surface acoustic wave (SAW) (f=30-150 MHz)
interacting in a magnetic field up to 7 T and in the temperature range 1.5-4K
with the 2D-electronic system of a GaAs/AlGaAs heterostructure has been studied
as a function of SAW intensity. In the region of delocalized electrons
nonlinear effects in the SAW attenuation could be explained by the heating of
electrons in the electric field of the piezoelectrically active SAW and could
be described in terms of the electronic temperature Te exceeding the lattice
temperature. In the integer Hall regime when the electrons are localized and
the temperature dependence of high-frequency conductivity is of an activation
nature the nonlinear behavior of the attenuation and sound velocity is
explained by the nonlinear percolation conductivity theory of Shklovskii.
Section
: 2