Photovoltaic effect in a gated two-dimensional electron gas in magnetic field

The photovoltaic effect induced by terahertz radiation in a gated two-dimensional electron gas in magnetic field is considered theoretically. It is assumed that the incoming radiation creates an ac voltage between the source and the gate and that the gate length is long compared to the damping length of plasma waves. In the presence of pronounced Shubnikov-de Haas (SdH) oscillations, an important source of nonlinearity is the oscillating dependence of the mobility on the ac gate voltage. This results in a photoresponse oscillating as a function of magnetic field, which is enhanced in the vicinity of the cyclotron resonance, in accordance with recent experiments. Another smooth component of the photovoltage, unrelated to SdH oscillations, has a maximum at cyclotron resonance.