Cold atom quantum memories and the telecom interface

Long-distance quantum information networks require information storage, retrieval and transmission at telecommunication wavelengths. A quantum memory and its interface to the telecom window based on cold rubidium in an optical lattice is described. With this system it has been demonstrated (i) interconversion of 795 and 1367 nm light with efficiency in excess of 50% and (ii) measurement of non-classical correlations between telecom light and atomic spin-wave excitations.