We study the in-plane stationary current caused by phototransitions between
the states of a double quantum well. The electric polarization of light has
both vertical and in-plane components. The stationary current originates from
the periodic vibration of electrons between two non-equivalent quantum wells
caused by the normal component of the alternating electric field with
simultaneous in-plane acceleration/deceleration by the in-plane component of
electric field. The quantum mechanism of the stationary current is conditioned
by in-plane transition asymmetry which appears due to the indirect
phototransitions with the participation of impurity scattering. The
photocurrent has a resonant character corresponding to the equality of the
photon energy to the distance between subbands. It is found that the current
appears as a response to the linear-polarized light.Comment: 6 pages, 2 figure