Terahertz-Field-Induced Tunneling Current With Nonlinear Effects In A Double Quantum Well Coupled To A Continuum

We have theoretically investigated the tunneling current induced by a terahertz (THz) field applied to an asymmetric double quantum well. The excitation couples an initially localized state to a nearby continuum of extended states. We have shown that the calculated current has similar features as those present in the optical spectra, such as interference effects due to the interaction between the continuum and the localized states, in addition to many-photon transition effects. The induced current is calculated as a function of the intensity of the THz field. A second THz field is used to yield nonlinear processes, useful to control the interference effects. We believe that part of the issues studied here can be useful for the integration of novel switching mechanisms based on optics (THz) and electronic current.