Our research project is focused on the development of a single photon source based on third order non-linearity in a cell of 87 Rubidium atoms through Four-Wave-Mixing process (FWM). In this process, a pair of co-propagating beams, a pump and a coupling, interact with the atomic ensemble and generate Stokes and anti-Stokes photon pairs. To fully characterize the spontaneous FWM at the single photon level, a homodyne detection scheme will be implemented. The heralded signal (anti-Stokes) photon will be mixed with a local oscillator and measured only when a single-photon detector, acting as a trigger, will have detected the idler (Stokes) photon. Within this context, we aim at engineering the generation of heralded single photons frequency-entangled states, exploiting the indistinguishability between two FWM processes under suitable pump and coupling driving conditions [1]. The frequency bandwidth of the generated photons makes them ideal to interact with systems like atoms and molecules. A first experimental test will be implemented adapting the entangled source to interact with our atomic system made by a Bose-Einstein condensate of 87 Rubidium realized with an atom-chip (see Figure) thus paving the way towards the long-standing goal of a quantum network of atomic clocks. (Image created by I. Mastroserio)

References

[1] A. Zavatta, M. Artoni, and G. La Rocca, Engineering of heralded narrowband color-entangled states. Phys. Rev. A 99, 031802(R) (2019).