STEADY-STATE TRANSPORT IN MESOSCOPIC SYSTEMS ILLUMINATED BY ALTERNATING-FIELDS

In this paper we present a Landauer-type expression for the time-averaged dc current in a mesoscopic device illuminated by a coherent ac field, assuming phase-breaking processes to be restricted to the contacts. This expression is derived starting from the nonequilibrium Green-function formalism which rigorously accounts for the exclusion principle. However, the (1 - f) factors that are often assumed do not appear in our expression. This does not affect the result if the transmission is reciprocal. But for traveling-wave fields the transmission is nonreciprocal even in zero magnetic fields and the magnitude of the resulting current is affected by the presence or absence of the (1 - f) factor.