Efficient spatiotemporal-vortex four-wave mixing in a semiconductor nanostructure

We propose a scheme to demonstrate spatiotemporal-vortex four-wave mixing (FWM) in an asymmetric semiconductor double quantum-well nanostructure. It is found that the orbital-angular-momentum (OAM) phase is transferred entirely from a unique OAM mode to the FWM field. Interestingly, by adjusting the detuning or the intensity of a control field, one can effectively modulate the phase and intensity of the FWM field. Also, we perform the superposition modes created by the interference between the FWM field and a same-frequency Laguerre-Gaussian mode, which show many interesting properties. Moreover, the conversion efficiency and quality of the output FWM field are studied. It is shown that the generated FWM mode has a maximum fidelity of approximately 100%. Our result may find potential applications in fundamental research and quantum technologies based on OAM light in solids.