Origin of intrinsic oscillations in double-barrier quantum-well systems

We present a theory accounting for the origin of high-frequency current oscillations in a double barrier quantum-well system. The origin of such current oscillations is traced to the development of a dynamic emitter quantum-well and the concomitant coupling of the energy levels in the double barrier quantum-well system. The relationship between the oscillation frequency and the energy level structure of the system is expressed as nu = DeltaE(0)/h: A self-consistent, time-dependent Wigner-Poisson numerical computer experiment is used to exhibit remarkable intrinsic, sustained current oscillations in the double-barrier quantum well at terahertz frequencies; and a procedure for calculating DeltaE(0), the energy difference at time t(0) (defined such that the contribution to the energy difference from the potential oscillation is zero) is also presented. The simulated oscillation frequency determined using the Wigner-Poisson analysis is in very good agreement with that calculated using a Schrodinger equation with a self-consistent potential determined from the Poisson equation. (C) 2003 Elsevier Science B.V. All rights reserved.