title: Temporal Multimode Storage of Entangled Photon Pairs.
abstract: Multiplexed quantum memories capable of storing and processing entangled photons are essential for the development of quantum networks. In this context, we demonstrate and certify the simultaneous storage and retrieval of two entangled photons inside a solid-state quantum memory and measure a temporal multimode capacity of ten modes. This is achieved by producing two polarization-entangled pairs from parametric down-conversion and mapping one photon of each pair onto a rare-earth-ion-doped (REID) crystal using the atomic frequency comb (AFC) protocol. We develop a concept of indirect entanglement witnesses, which can be used as Schmidt number witnesses, and we use it to experimentally certify the presence of more than one entangled pair retrieved from the quantum memory. Our work puts forward REID-AFC as a platform compatible with temporal multiplexing of several entangled photon pairs along with a new entanglement certification method, useful for the characterization of multiplexed quantum memories.
authors.affiliation: Groupe de Physique Appliquée, Université de Genève, CH-1211 Genève, Switzerland.
authors.forename: Alexey
authors.initials: A
authors.lastname: Tiranov
authors.affiliation: Groupe de Physique Appliquée, Université de Genève, CH-1211 Genève, Switzerland.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Strassmann
authors.affiliation: Groupe de Physique Appliquée, Université de Genève, CH-1211 Genève, Switzerland.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Lavoie
authors.affiliation: Département Physique Théorique, Université de Genève, CH-1211 Genève, Switzerland.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Brunner
authors.affiliation: Groupe de Physique Appliquée, Université de Genève, CH-1211 Genève, Switzerland.|Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria.
authors.forename: Marcus
authors.initials: M
authors.lastname: Huber
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: Varun B
authors.initials: VB
authors.lastname: Verma
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: Sae Woo
authors.initials: SW
authors.lastname: Nam
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Mirin
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: Adriana E
authors.initials: AE
authors.lastname: Lita
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, California 91109, USA.
authors.forename: Francesco
authors.initials: F
authors.lastname: Marsili
authors.affiliation: Groupe de Physique Appliquée, Université de Genève, CH-1211 Genève, Switzerland.
authors.forename: Mikael
authors.initials: M
authors.lastname: Afzelius
authors.affiliation: Groupe de Physique Appliquée, Université de Genève, CH-1211 Genève, Switzerland.
authors.forename: Félix
authors.initials: F
authors.lastname: Bussières
authors.affiliation: Groupe de Physique Appliquée, Université de Genève, CH-1211 Genève, Switzerland.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Gisin