title: Generation of Light with Multimode Time-Delayed Entanglement Using Storage in a Solid-State Spin-Wave Quantum Memory.
abstract: Here, we demonstrate generating and storing entanglement in a solid-state spin-wave quantum memory with on-demand readout using the process of rephased amplified spontaneous emission (RASE). Amplified spontaneous emission (ASE), resulting from an inverted ensemble of Pr^{3+} ions doped into a Y_{2}SiO_{5} crystal, generates entanglement between collective states of the praseodymium ensemble and the output light. The ensemble is then rephased using a four-level photon echo technique. Entanglement between the ASE and its echo is confirmed and the inseparability violation preserved when the RASE is stored as a spin wave for up to 5  μs. RASE is shown to be temporally multimode with almost perfect distinguishability between two temporal modes demonstrated. These results pave the way for the use of multimode solid-state quantum memories in scalable quantum networks.
authors.affiliation: Centre for Quantum Computation and Communication Technology, Laser Physics Centre, Australian National University, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: Kate R
authors.initials: KR
authors.lastname: Ferguson
authors.affiliation: European Space Agency, NL-2200 AG, Noordwijk, The Netherlands.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Beavan
authors.affiliation: Jack Dodd Centre for Photonics and Ultra-Cold Atoms, Department of Physics, University of Otago, Dunedin 9016, New Zealand.
authors.forename: Jevon J
authors.initials: JJ
authors.lastname: Longdell
authors.affiliation: Centre for Quantum Computation and Communication Technology, Laser Physics Centre, Australian National University, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Sellars