Laser-assisted self-induced Feshbach resonance for controlling heteronuclear quantum gas mixtures

We propose a type of Feshbach resonance occurring when two different ultracold atoms in their ground state
undergo an s-wave collision in the presence of a laser. The collisional levels of the atom pair are coupled by
the laser to a rovibrational molecular level of the same electronic ground state: We name it a laser-assisted
self-induced Feshbach resonance. This mechanism, valid for all heteronuclear quantum gas mixtures, is analyzed
on the example of ultracold 87Rb and 84Sr atoms for which the resonant laser frequency falls in the subterahertz
range. The interspecies scattering length can be controlled with the laser frequency and intensity without atom
loss. Moreover, chirping slowly, the frequency allows for the adiabatic formation of ultracold 87Rb 84Sr molecules
in a manner very similar to a magnetic Feshbach resonance. A stimulated Raman adiabatic passage follows for
stabilizing the molecules in their rovibronic ground state.