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arXiv · 1006.5517

Quantum Interference of Stored Coherent Spin-wave Excitations in a Two-channel Memory

Hai Wang·Shujing Li·Zhongxiao Xu·Xingbo Zhao·Lijun Zhang·Jiahua Li·Yuelong Wu·Changde Xie·Kunchi Peng·Min Xiao
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Abstract

Quantum memories are essential elements in long-distance quantum networks and quantum computation. Significant advances have been achieved in demonstrating relative long-lived single-channel memory at single-photon level in cold atomic media. However, the qubit memory corresponding to store two-channel spin-wave excitations (SWEs) still faces challenges, including the limitations resulting from Larmor procession, fluctuating ambient magnetic field, and manipulation/measurement of the relative phase between the two channels. Here, we demonstrate a two-channel memory scheme in an ideal tripod atomic system, in which the total readout signal exhibits either constructive or destructive interference when the two-channel SWEs are retrieved by two reading beams with a controllable relative phase. Experimental result indicates quantum coherence between the stored SWEs. Based on such phase-sensitive storage/retrieval scheme, measurements of the relative phase between the two SWEs and Rabi oscillation, as well as elimination of the collapse and revival of the readout signal, are experimentally demonstrated.

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Hai Wang, Shujing Li, Zhongxiao Xu, Xingbo Zhao, Lijun Zhang, Jiahua Li, Yuelong Wu, Changde Xie, Kunchi Peng, Min Xiao. 2010-06-29. Quantum Interference of Stored Coherent Spin-wave Excitations in a Two-channel Memory. https://doi.org/10.1103/physreva.83.043815

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