Two-photon optical shielding of collisions between ultracold polar molecules

Abstract

We propose a method to engineer repulsive long-range interactions between ultracold ground-state molecules using optical fields, thus preventing short-range collisional losses. It maps the microwave coupling recently used for collisional shielding onto a two-photon transition and takes advantage of optical control techniques. In contrast to one-photon optical shielding [Xie, Phys. Rev. Lett. 125, 153202 (2020)0031-900710.1103/PhysRevLett.125.153202], this scheme avoids heating of the molecular gas due to photon scattering. The proposed protocol, exemplified for Na23K39, should be applicable to a large class of polar diatomic molecules.