  We present a microscopic theory of a photon drag effect that appears in a
Bose-Einstein condensate of neutral particles, considering indirect excitons in
a double quantum well nanostructure under the action of a circularly polarized
electromagnetic field. It is shown that the dynamical polarization of excitons
results in a resonant behavior of the exciton photon drag flux when the
frequency of light is close to the gap between two energy levels of internal
exciton motion. Specifically, we consider the ground and first excited energy
states characterized by the angular momentum difference $\pm 1$, and thus, the
helicity of light matters. We show that the resulting drag current is caused by
both Bose-condensed particles and the particles in the normal state. As a
result, the total current represents a superposition of thresholdlike and
resonant contributions, - property, which can be used in frequency-selective
photodetection.
