Centre for Quantum Computation and Communication Technology, Laser Physics Centre, Australian National University, Canberra, Australian Capital Territory 2601, Australia.
European Space Agency, NL-2200 AG, Noordwijk, The Netherlands.
Phys Rev Lett. 2016 Jul 8;117(2):020501. doi: 10.1103/PhysRevLett.117.020501. Epub 2016 Jul 6.
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.
在这里，我们通过再相位放大自发辐射（RASE）过程展示了利用固态自旋波量子存储器进行按需读取的纠缠态产生和存储。在 Y2SiO5晶体中掺杂 Pr3+离子的反转集合体产生的放大自发辐射（ASE），在镨集合体的集体态和输出光之间产生纠缠。然后使用四能级光子回波技术对集合体进行再相位。当 RASE 作为自旋波存储长达 5μs 时，确认了 ASE 与其回波之间的纠缠，并保持了不可分离性违反。结果表明，RASE 具有时间多模特性，两个时间模式之间具有几乎完美的可分辨性。这些结果为在可扩展量子网络中使用多模固态量子存储器铺平了道路。
