Quantum non-linear optics mediated by Rydberg excitations on sub-wavelength atom array*

Strong interaction between highly excited Rydberg atoms has emerged as a great tool to study photon-photon interaction in the last fifteen years. A fundamental challenge,  however,  is the loss of the photon as a result of scattering from the atoms or decoherence due to collisions between ground state and Rydberg atoms. A scalable sub-wavelength atomic array that is very similar to a diffraction grating and emits in only certain modes might solve this problem. Recently, there have been computational^[1] and experimental^[2] studies where sub-wavelength array has been shown to behave like a near-perfect mirror under certain conditions.

Here, we present our efforts towards building an array of Rb-87 atoms in a bottom-up method using optical tweezers. We plan to create Rydberg electromagnetically induced transparency (EIT) on the array and investigate Rydberg-mediated quantum non-linearities characterized by photon-photon correlations. Furthermore, the low-loss properties of the array can make this an ideal platform for applications such as photon-photon gates and creation of highly entangled states.

[1] Phys. Rev. Lett. 118, 113601 (2017)

[2] Nature 583, 369-374 (2020)