Response of a Bloch oscillator to a THz‐field

Abstract

Abstract In this paper we report on the observation of response of a Bloch oscillator at room temperature to a THz‐field of a frequency larger than the Bloch frequency. The oscillator consisted of a semiconductor superlattice structure, with an applied dc voltage giving rise to a dc electron drift current. Submitting the oscillator to a field at a frequency of 3.3 THz caused a sizeable reduction of the current; the THz‐field was generated by use of intense THz‐radiation pulses focused on an antenna coupled to the superlattice. We attribute the THz‐field induced reduction of the current to a frequency modulation of the Bloch oscillations of electrons at the frequency of the THz‐field, leading to reduction of the electron drift velocity and, consequently, of the current.