Towards highly multimode optical quantum memory for quantum repeaters
Towards highly multimode optical quantum memory for quantum repeaters
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DOI：
10.1103/physreva.93.032327
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发表时间：
2016-03-21
影响因子：
2.9
通讯作者：
Afzelius, Mikael
中科院分区：
文献类型：
--
作者：
Jobez, Pierre;Timoney, Nuala;Afzelius, Mikael
由于光纤损耗，通过光纤进行的长距离量子通信目前仅限于几百公里。量子中继器可以将这一限制扩展到大陆距离。量子中继器的大多数方法需要高度多模量子存储器，以达到高通信速率。原子频率梳状存储器方案原则上可以实现高时间多模存储，而不牺牲存储器效率。然而，以前的演示受到了创建高分辨率原子梳的困难的阻碍，这降低了多模存储的效率。在这篇文章中，我们提出了一个梳准备方法，允许一个固定的内存带宽，以增加多模容量。我们将该方法应用于Eu-151（3+）掺杂的Y2 SiO 5晶体，在其中，我们演示了存储100模式为51 μ s使用AFC回波计划（延迟线存储器）和存储50模式为0.541毫秒使用AFC自旋波存储器（按需存储器）。我们还简要地讨论了最终的多模限制所施加的光退相干率，对于一个固定的存储器带宽。
Long-distance quantum communication through optical fibers is currently limited to a few hundreds of kilometres due to fiber losses. Quantum repeaters could extend this limit to continental distances. Most approaches to quantum repeaters require highly multimode quantum memories in order to reach high communication rates. The atomic frequency comb memory scheme can in principle achieve high temporal multimode storage, without sacrificing memory efficiency. However, previous demonstrations have been hampered by the difficulty of creating high-resolution atomic combs, which reduces the efficiency for multimode storage. In this article we present a comb preparation method that allows one to increase the multimode capacity for a fixed memory bandwidth. We apply the method to a Eu-151(3+)-doped Y2SiO5 crystal, in which we demonstrate storage of 100 modes for 51 mu s using the AFC echo scheme (a delay-line memory) and storage of 50 modes for 0.541 ms using the AFC spin-wave memory (an on-demand memory). We also briefly discuss the ultimate multimode limit imposed by the optical decoherence rate, for a fixed memory bandwidth.