Résumé
Detection of THz radiation by a Field Effect Transistor InGaAs/InAlAs transistor was investigated at 4.2 K as a function of the magnetic field and gate voltage. We observed oscillations of the photovoltaic signal analogous to Shubnikov-de Haas oscillations, as well as their strong enhancement at the cyclotron resonance conditions. The results are successfully quantitatively described within the frame of a recent theory, taking into account a new source of nonlinearity related to Shubnikov-de Haas effect. We show that the detection is due to gated plasmon.