Suppression of current through an Esaki-Tsu GaAs/AlAs superlattice by millimeter wave irradiation

We report the observation of suppression of the de current through an Esaki-Tsu GaAs/AlAs superlattice (that shows a negative differential conductance due to Bloch oscillations of miniband electrons) caused by irradiation with millimeter wave radiation (frequency 78 GHz). A theoretical analysis of the de current indicated that the high-frequency electric current followed the high-frequency field with a response time smaller than the period (similar to 10(-11) s) of the field. Our experiment, with the superlattice at room temperature, demonstrates that the Esaki-Tsu superlattice is suitable for ultrafast millimeter wave detection and other high-frequency applications. (C) 1996 American Institute of Physics.