  The realization of a future quantum Internet requires processing and storing
quantum information at local nodes, and interconnecting distant nodes using
free-space and fibre-optic links. Quantum memories for light are key elements
of such quantum networks. However, to date, neither an atomic quantum memory
for non-classical states of light operating at a wavelength compatible with
standard telecom fibre infrastructure, nor a fibre-based implementation of a
quantum memory has been reported. Here we demonstrate the storage and faithful
recall of the state of a 1532 nm wavelength photon, entangled with a 795 nm
photon, in an ensemble of cryogenically cooled erbium ions doped into a 20
meter-long silicate fibre using a photon-echo quantum memory protocol. Despite
its currently limited efficiency and storage time, our broadband light-matter
interface brings fibre-based quantum networks one step closer to reality.
Furthermore, it facilitates novel tests of light-matter interaction and
collective atomic effects in unconventional materials.
