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arXiv · 1602.00491

Dual-rail optical gradient echo memory

Daniel B. Higginbottom·Jiao Geng·Geoff T. Campbell·Mahdi Hosseini·Ming Tao Cao·Ben M. Sparkes·Julian Bernu·Nick P. Robins·Ping Koy Lam·Ben C. Buchler
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Abstract

We introduce a scheme for the parallel storage of frequency separated signals in an optical memory and demonstrate that this dual-rail storage is a suitable memory for high fidelity frequency qubits. The two signals are stored simultaneously in the Zeeman-split Raman absorption lines of a cold atom ensemble using gradient echo memory techniques. Analysis of the split-Zeeman storage shows that the memory can be configured to preserve the relative amplitude and phase of the frequency separated signals. In an experimental demonstration dual-frequency pulses are recalled with 35% efficiency, 82% interference fringe visibility, and 6 degrees phase stability. The fidelity of the frequency-qubit memory is limited by frequency-dependent polarisation rotation and ambient magnetic field fluctuations, our analysis describes how these can be addressed in an alternative configuration.

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Daniel B. Higginbottom, Jiao Geng, Geoff T. Campbell, Mahdi Hosseini, Ming Tao Cao, Ben M. Sparkes, Julian Bernu, Nick P. Robins, Ping Koy Lam, Ben C. Buchler. 2016-02-01. Dual-rail optical gradient echo memory. https://doi.org/10.1364/oe.23.024937

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