Optical vortex transfer via Four-Wave-Mixing in a double quantum dot system with a closed interaction loop

Abstract

We propose a scheme to exchange optical vortices via four wave mixing (FWM) in an asymmetric double quantum dot (DQD) characterized by five energy levels. The inter-well cross coupling between neighboring wells originates a five-level closed-loop atomic configuration which makes the linear susceptibility of probe and generated beams to be phase-dependent. It is found that optical vortex transfer from a field carrying orbital angular momentum (OAM) to a generated FWM field can be achieved by adjusting the Rabi frequency and detuning of two control fields and by changing the relative phase of the driving fields. In addition, the FWM field can be significantly enhanced and the phase twist can be controlled and almost completely suppressed if proper laser parameters are chosen. Such a solid-state system may be very practical due to the flexibility of QDs in the implementation of high-efficient frequency and OAM conversion devices for quantum information processing.