Optical control of magnetic Feshbach resonances in Bose gases

• Two optical fields can steer effectively magnetic Feshbach resonance in Bose gas.
• Two optical fields suppress inelastic loss and change scattering length.
• The atom–molecule interaction has some effect on scattering length.

We theoretically investigate optical control of magnetic Feshbach resonance in Bose gases with two optical fields. The two optical fields couple two ground states through an excited state. Compared with the usual single-optical scheme, two optical fields can greatly suppress the inelastic loss resulting from spontaneous emission by the destructive quantum interference. Using the mean field theory, the analytical formula of the scattering length is obtained. The results show that the scattering length can be modified in a large range by changing the Rabi frequency or the optical field frequency. The strong atom–molecule interaction has obvious effect on the scattering length.