Terahertz-field induced tunneling current with non-linear effects in a double quantum well coupled to a continuum

TL;DR

This paper presents a theoretical study of terahertz-induced tunneling currents in a double quantum well, revealing interference and non-linear effects that could enable optical-electronic switching mechanisms.

Contribution

It introduces a theoretical model showing how THz fields induce tunneling currents with controllable non-linear and interference effects in quantum wells.

Findings

Current exhibits interference effects similar to optical spectra.

Non-linear processes can be controlled using a second THz field.

Potential for novel optical-electronic switching mechanisms.

Abstract

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 non-linear processes, useful to control the interference effects. We believe that part of the issues studied here can be usefull for the integration of novel switching mechanisms based on optics (THz) and electronic current.