ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain.
ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain and ICREA-Institució Catalana de Recerca i Estudis Avançats, 08015 Barcelona, Spain.
Phys Rev Lett. 2014 Jan 31;112(4):040504. doi: 10.1103/PhysRevLett.112.040504.
We report on experiments demonstrating the reversible mapping of heralded single photons to long-lived collective optical atomic excitations stored in a Pr3+:Y2SiO5 crystal. A cavity-enhanced spontaneous down-conversion source is employed to produce widely nondegenerate narrow-band (≈2 MHz) photon pairs. The idler photons, whose frequency is compatible with telecommunication optical fibers, are used to herald the creation of the signal photons, compatible with the Pr3+ transition. The signal photons are stored and retrieved using the atomic frequency comb protocol. We demonstrate storage times up to 4.5 μs while preserving nonclassical correlations between the heralding and the retrieved photon. This is more than 20 times longer than in previous realizations in solid state devices, and implemented in a system ideally suited for the extension to spin-wave storage.
我们报告了实验结果，证明了单光子的可反转映射到存储在 Pr3+:Y2SiO5 晶体中的长寿命集体光学原子激发。利用腔增强自发下转换源产生宽非简并窄带（≈2 MHz）光子对。频率与电信光纤兼容的闲频光子被用来标记信号光子的产生，信号光子与 Pr3+ 跃迁兼容。利用原子频梳协议存储和检索信号光子。我们演示了长达 4.5 μs 的存储时间，同时保持了标记和检索光子之间的非经典相关性。这比以前在固态器件中的实现时间长 20 多倍，并且在一个非常适合扩展到自旋波存储的系统中实现。
