  We study theoretically transverse photoconductivity induced by circularly
polarized radiation, i.e. the photovoltaic Hall effect, and linearly polarized
radiation causing intraband optical transitions in two-dimensional electron gas
(2DEG). We develop a microscopic theory of these effects based on analytical
solution of the Boltzmann equation for arbitrary electron spectrum and
scattering mechanism. We calculate the transverse photoconductivity of 2DEG
with parabolic and linear dispersion for short-range and Coulomb scatterers at
different temperatures. We show that the transverse electric current is
significantly enhanced at frequencies comparable to the inverse energy
relaxation time, whereas at higher frequencies the excitation spectrum and the
direction of current depend on the scattering mechanism. We also analyse the
effect of thermalization processes caused by electron-electron collisions on
the photoconductivity.
