THEORETICAL INVESTIGATION OF CURRENT-NOISE CHARACTERISTICS IN FINITE SEMICONDUCTOR SUPERLATTICE WITH CORRELATED THICKNESS RANDOMNESS

Using a transmission probability formalism, we perform theoretical cal culations for the current-noise characteristics of a finite semiconduc tor superlattice with correlated thickness randomness in which the thi cknesses of barriers are regular but those of wells are partially rand om. The transmission probability is calculated by the use of an exact Airy-function formalism combined with a transfer matrix technique. We show that the tunneling resonance, owing to the existence of reflectio nless electron waves in the absence of electric field, is sensitively suppressed by the applied held, leading to a special legion of negativ e differential resistivity at low bias voltages in the I-V curve. The current fluctuations near the peak of the I-V curve are decreased from the usual shot-noise values due to the large transmission of the refl ectionless waves. The results may shed light on the possibility of exp loiting the structure in designing resonant-tunneling systems that req uire optimum sensitivity to applied electric held. (C) 1995 American I nstitute of Physics.