Controlling Feshbach-optimized photoassociation of ultracold atoms with non-resonant laser field

We investigate theoretically the formation of ultracold $^{\mathrm{40}}$K$^{\mathrm{87}}$Rb molecules using Feshbach-optimized photoassociation controlled by non-resonant laser field. A scattering resonance can greatly enhance the photoassociation rate via increasing the number of atom pairs at short interatomic separations. Here a non-resonant laser field is employed to induce the coupling between different partial waves and modify the scattering resonance in their position and width. By tuning the intensity of the non-resonant laser field, the photoassociation rate is enhanced by several orders of magnitude with a fixed magnetic field. The employment of a non-resonant laser field gives an additional approach of photoassociation rate control and is much more feasible for the experiment than a dc electric field.