Raman Storage of Quasideterministic Single Photons Generated by Rydberg Collective Excitations in a Low-Noise Quantum Memory

We demonstrate the storage and retrieval of an on-demand single photon generated by a collective Rydberg excitation in ultra-low noise Raman quantum memory located different cold atomic ensemble. generate photons on demand exciting cloud Rubidium atoms off resonantly to state, with generation probability up 15 $\%$ per trial. then show that can be stored retrieved efficiency 21 floor $p_n= 2.3(3) \times 10^{-4}$ trial memory. This leads signal-to-noise ratio ranging from 11 26 for depending input probability, which allows us observe significant antibunching. also evaluate performances as built-in unbalanced temporal beam splitter, tunable varying write-in control pulse intensity. In addition, we used single-photon waveshape. These results are step forward implementation efficient quantum-repeater links using sources.