Microwave shielding of ultracold polar molecules*

We use microwaves to engineer repulsive long-range interactions between ultracold polar molecules [1]. The resulting shielding suppresses various loss mechanisms and provides large elastic cross sections. Hyperfine interactions limit the shielding under realistic conditions, but a magnetic field allows suppression of the losses to below 10^-14 cm³ s^-1 . The mechanism and optimum conditions for shielding differ substantially from those proposed by Gorshkov et al. [Phys. Rev. Lett. 101, 073201 (2008)], and do not require cancelation of the long-range dipole-dipole interaction that is vital to many applications.

[1] T. Karman and J.M Hutson, Phys. Rev. Lett. 121, 163401 (2018)