An experimental setup to generate narrowband bi-photons via four-wave mixing in cold atoms

• Main Authors: A´ngeles-Aguillo´n, I.F (Author), Arias-Te´llez, N. (Author), Gutie´rrez-Arenas, R.A (Author), Ja´uregui, R. (Author), Mart´ınez-Cara, D. (Author), Mart´ınez-Vallejo, A. (Author), Mendoza-Lo´pez, L.A (Author), Sahagu´n Sa´nchez, D. (Author), Torres, Y.M (Author), Villegas-Aguilar, L.Y (Author)
• Format: Article
• Language: English
• Published: Sociedad Mexicana de Fisica 2022
• Subjects: Bi-photons; cold atoms; four wave mixing; quantum information; quantum networks
• Online Access: View Fulltext in Publisher

 We present our recently-built experimental setup designed to generate near-infrared and narrow-band correlated photon pairs by inducing four-wave mixing in a cold gas of 87Rb atoms confined in a magneto-optical trap. The experimental setup and its automation and control approach are described in detail. A characterization of the optical density of the atomic ensemble as well as the basic statistical measurements of the generated light are reported. The non-classical nature of the photon pairs is confirmed by observing a violation of Cauchy-Schwarz inequality by a factor of 5.6 × 105 in a Hanbury Brown – Twiss interferometer. A 1/e coherence time for the heralded, idler photons of 4. 4 ± 0. 1 ns is estimated from our observations. We are able to achieve a value of 104 s− 1 pair-detection-rate, which results in a spectral brightness of 280 (MHz s)− 1. The combination of high brightness and narrow-band spectrum makes this photon-pair source a viable tool in fundamental studies of quantum states and opens the door to use them in quantum technologies. © 2022