Magnetic field dependence of phonon-induced drag current of 2D carriers

The magnetic field dependence of the drag current induced by beams of acoustic phonons is studied in a 2D gas of carriers, formed in a heterostructure. This drag current is related to the velocity of the center of mass of the gas. The elimination of the degrees of freedom related to the relative motion of the carriers leads to a Langevin equation for the center-of-mass position vector. From this equation one can obtain an expression for the induced current density which depends on carrier density-density correlation functions. An explicit formula for the time-integrated current density is derived taking into account all intra and inter Landau level transitions. Corresponding numerical results are in good agreement with the experimental patterns. PACS numbers: 63.20.Kr, 73.40.-c.