On a new photogalvanic effect due to free-carrier absorption

A new photocurrent induced by optical orientation of free carriers under intraband absorption is theoretically investigated. Using a one-band model it is shown that this current originates from interferences between harmonic and anharmonic processes of the electron-phonon interaction. A general expression for the current is derived for both, linear and circular polarized light. As an example the temperature dependence of the current is calculated for tellurium. (author)