Enhancement and Suppression of Four wave mixing in coupled semiconductor quantum dot-gold grating systems

TL;DR

This paper demonstrates how coupling quantum dots with a gold grating can controllably enhance or suppress four wave mixing processes, revealing underlying mechanisms and the impact of quantum dot coupling.

Contribution

It introduces a method to control FWM in quantum dot-gold systems by tuning quantum emitter properties, showing significant enhancement with coupled quantum dots.

Findings

Suppression of FWM due to Electromagnetic Induced Transparency.

Resonance enhancement of FWM when conditions are met.

Coupled quantum dots significantly increase FWM enhancement.

Abstract

We show that, Four wave mixing (FWM) processes of grating can be controlled by the presence of interactions with a quantum dot or a molecule made by coupled quantum dots. By choosing the appropriate level spacing for the quantum emitter, one can either suppress or enhance the Four wave mixing process. We revel theoretically the underlying mechanism for this effect. (i) Suppression in FWM intensity occurs simply because induced Electromagnetic Induced Transparency does not allow the excitation at converted FWM frequency. (ii) Enhancement emerges since FWM process can be brought to resonance. Path interference effect cancels the nonresonant frequency terms. Furthermore, we have also shown that in case of coupled quantum dots enhancement increases significantly as compared to the case of a single quantum dot.