Interfacing individual ultracold polar molecules and Rydberg atoms in optical tweezers

We envision a hybrid quantum network comprised of individually trapped polar molecules interfaced with Rydberg atoms. The nodes of the network are single molecules, where information is stored. The links are Rydberg atoms which mediate strong, long-range interactions between nodes and read out their states non-destructively. This hybrid network leverages the rich structure of long-lived internal states provided by molecules and the strong, controllable interactions provided by the Rydberg atoms.

 

Here we report our experimental progress towards this goal. We produce single RbCs molecules in optical tweezers which allows for single-site control and imaging. Alongside the molecules, excess Rb (or Cs) atoms are prepared in the motional ground state and excited to Rydberg states with a two-photon excitation scheme. For an atom-molecule separation of 310(40) nm, we first demonstrate blockade of the transition to the Rydberg state due to the charge-dipole interaction with the molecule in the rotational ground state. We then demonstrate resonant dipole-dipole interactions between individual atoms and molecules by tuning the energy difference between a pair of Rydberg levels to match the spacing of a rotational transition in the molecule. This enhanced interaction allows for observation of blockade at micron-scale separations and provides a route to non-destructive readout of the state of the molecule and Rydberg-mediated entanglement of a pair of molecules.