The phonon-induced drag of charge carriers in heterostructures in weak magnetic fields

The kinetic description of the response of two-dimensional gases of carriers in a weak magnetic field to pulsed beams of bulk long-wavelength acoustic phonons is presented. It is assumed that a surface element with radius vector r filled with this gas has an elongated form characterized by the unit vector <(eta)over cap>. The component eta of the time-integrated current density is calculated. This quantity depends on a time tau(e) characterizing the elastic scattering of carriers by defects and on the cyclotron frequency omega(c) via dimensionless parameter theta(c) tau(e). Using the obtained formula for the eta component of time-integrated current density, we calculate suitable response patterns and compare them with results of our experiments for a gas of holes.