Quantum Storage of Heralded Polarization Qubits in Birefringent and Anisotropically Absorbing Materials
Quantum Storage of Heralded Polarization Qubits in Birefringent and Anisotropically Absorbing Materials
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DOI：
10.1103/physrevlett.108.190503
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发表时间：
2012-05-10
影响因子：
8.6
通讯作者：
Gisin, Nicolas
中科院分区：
文献类型：
--
作者：
Clausen, Christoph;Bussieres, Felix;Gisin, Nicolas
将量子信息编码成单个光子进行存储是基于量子中继器的长距离量子通信和光量子信息处理的重要组成部分。然而，光子偏振量子比特的存储是困难的，因为许多材料是双折射的，并且具有偏振相关的吸收。在这里，我们提出了一个简单的方案，消除这些偏振效应，我们证明它通过存储到固态量子存储器中的偏振量子比特。量子存储器是用掺有稀土离子的双轴硅酸钇（Y2 SiO 5）晶体实现的。从过滤的自发参量下转换源产生的预示的单光子被存储，并且所检索的偏振态的量子态层析成像显示出97.5 +/-0.4%的平均保真度，这显著高于用测量和准备策略可实现的保真度。
Storage of quantum information encoded into heralded single photons is an essential constituent of long-distance quantum communication based on quantum repeaters and of optical quantum information processing. The storage of photonic polarization qubits is, however, difficult because many materials are birefringent and have polarization-dependent absorption. Here we present a simple scheme that eliminates these polarization effects, and we demonstrate it by storing heralded polarization qubits into a solid-state quantum memory. The quantum memory is implemented with a biaxial yttrium orthosilicate (Y2SiO5) crystal doped with rare-earth ions. Heralded single photons generated from a filtered spontaneous parametric down-conversion source are stored, and quantum state tomography of the retrieved polarization state reveals an average fidelity of 97.5 +/- 0.4%, which is significantly higher than what is achievable with a measure-and-prepare strategy.