HIGH-FREQUENCY MODULATION OF CURRENT IN TUNNEL-COUPLED QUANTUM-WELLS BY TRANSVERSE RADIATION IN THE TERAHERTZ RANGE

The modulation of a longitudinal current in double quantum wells by a transverse voltage in the terahertz frequency range is calculated. A q uantum kinetic equation which allows for the contributions of a pair o f asymmetric tunnel-coupled levels to the resonant response is solved (the difference in effective mass or the asymmetric scattering in the left- and right-hand quantum wells is also taken into account). These structural features lead to conversion of the modulating voltage into a high-frequency longitudinal current. The calculated longitudinal-tra nsverse nonlinear susceptibility determines the conditions needed for creating an efficient field-effect transistor circuit that would use p umping in the terahertz range instead of a transverse control voltage. (C) 1998 American Institute of Physics.