19 January 2017

Our group demonstrated the storage of single photons in a strongly nonlinear medium based on highly excited Rydberg atoms. The scientific results of this study have been published in Nature Communications.

Strong interaction between two single photons is a long standing and important goal in quantum photonics. This would enable a new regime of nonlinear optics and unlock several applications in quantum information science, including photonic quantum gates and deterministic Bell-state measurements. In the context of quantum networks, it would be important to achieve interactions between single photons from independent photon pairs storable in quantum memories. So far, most experiments showing nonlinearities at the single-photon level have used weak classical input light. Here we demonstrate the storage and retrieval of a paired single photon emitted by an ensemble quantum memory in a strongly nonlinear medium based on highly excited Rydberg atoms. We show that nonclassical correlations between the two photons persist after retrieval from the Rydberg ensemble. Our result is an important step towards deterministic photon–photon interactions, and may enable deterministic Bell-state measurements with multimode quantum memories.

The research team that participated in this study includes Emanuele Distante, Pau Farrera, Auxiliadora Padrón-Brito, David Paredes-Barato, Georg Heinze and Prof. Hugues de Riedmatten.

Reference :

Storing single photons emitted by a quantum memory on a highly excited Rydberg state
Emanuele Distante, Pau Farrera, Auxiliadora Padrón-Brito, David Paredes-Barato, Georg Heinze and Prof. Hugues de Riedmatten
Nature Communications 8, 14072 (2017)