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arXiv 1707.09372quant-ph
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空间多路复用冷原子包壳中偏振量子比特的高效量子存储

Highly-Efficient Quantum Memory for Polarization Qubits in a Spatially-Multiplexed Cold Atomic Ensemble

P. Vernaz-Gris, K. Huang, M. Cao, A. S. Sheremet, J. Laurat

摘要:

用于飞行光学量子比特的量子存储器是量子信息科学和技术中广泛应用的关键使能器。一个关键的品质因数是整体存储和检索效率。到目前为止,尽管最近在光脉冲的高效存储方面取得了成就,但量子比特的存储效率有限。在这里,我们报告的极化量子位的量子存储器,结合了平均条件保真度超过99%和效率等于(68 $\pm$ 2)%,从而证明了一个可逆的量子位映射,更多的信息被检索比丢失。量子比特在单光子水平上用弱相干态编码,存储器基于铯原子的细长激光冷却系综中的电磁诱导透明性,空间复用用于双轨存储。这种实现方式在两个轨道上都保持了较高的光学深度,而不会在多路复用和存储效率之间折衷。我们的工作为未来量子网络功能和先进光子电路的测试提供了一个有效的节点。

英文摘要:

Quantum memory for flying optical qubits is a key enabler for a wide range of applications in quantum information science and technology. A critical figure of merit is the overall storage-and-retrieval efficiency. So far, despite the recent achievements of efficient memories for light pulses, the storage of qubits has suffered from limited efficiency. Here we report on a quantum memory for polarization qubits that combines an average conditional fidelity above 99% and an efficiency equal to (68$\pm$ 2)%, thereby demonstrating a reversible qubit mapping where more information is retrieved than lost. The qubits are encoded with weak coherent states at the single-photon level and the memory is based on electromagnetically-induced transparency in an elongated laser-cooled ensemble of cesium atoms, spatially multiplexed for dual-rail storage. This implementation preserves high optical depth on both rails, without compromise between multiplexing and storage efficiency. Our work provides an efficient node for future tests of quantum network functionalities and advanced photonic circuits.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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