Dynamical instabilities andI−Vcharacteristics in resonant tunneling through double-barrier quantum well systems

Abstract

Based on our time-dependent numerical simulation results of a resonant tunneling structure, a resonant tunneling theory for double-barrier quantum well systems (DBQWS's) is presented. The origin of intrinsic high-frequency current oscillation in DBQWS's, a long-time unsolved device physics problem, is explained, in terms of a time-dependent energy-level coupling model (TDELCM) as the result of the coupling between the emitter quantum well and the main quantum well and the wave-corpuscle duality of electrons. The origin of the intrinsic high-frequency current oscillation in DBQWS's and that of the hyteresis and plateaulike structure in $I\ensuremath{-}V$ curves are two different aspects of the problem. A qualitative analysis of the creation of the hyteresis and plateaulike structure in $I\ensuremath{-}V$ curves is also given. The TDELCM sets the foundation of the time-independent energy-level coupling model that was presented in our recent paper [P. Zhao et al., J. Appl. Phys. 87, 1337 (2000)]. It presents insight into the whole process of resonant tunneling through a DBQWS.