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arXiv · 1910.08009

Optical storage for 0.53 seconds in a solid-state atomic frequency comb memory using dynamical decoupling

Adrian Holzäpfel·Jean Etesse·Krzysztof T. Kaczmarek·Alexey Tiranov·Nicolas Gisin·Mikael Afzelius
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Abstract

Quantum memories with long storage times are key elements in long-distance quantum networks. The atomic frequency comb (AFC) memory in particular has shown great promise to fulfill this role, having demonstrated multimode capacity and spin-photon quantum correlations. However, the memory storage times have so-far been limited to about one millisecond, realized in a Eu${}^{3+}$ doped Y${}_2$SiO${}_5$ crystal at zero applied magnetic field. Motivated by studies showing increased spin coherence times under applied magnetic field, we developed a AFC spin-wave memory utilizing a weak 15 mT magnetic field in a specific direction that allows efficient optical and spin manipulation for AFC memory operations. With this field configuration the AFC spin-wave storage time increased to 40 ms using a simple spin-echo sequence. Furthermore, by applying dynamical decoupling techniques the spin-wave coherence time reaches 530 ms, a 300-fold increase with respect to previous AFC spin-wave storage experiments. This result paves the way towards long duration storage of quantum information in solid-state ensemble memories.

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Adrian Holzäpfel, Jean Etesse, Krzysztof T. Kaczmarek, Alexey Tiranov, Nicolas Gisin, Mikael Afzelius. 2020-04-24. Optical storage for 0.53 seconds in a solid-state atomic frequency comb memory using dynamical decoupling. https://doi.org/10.1088/1367-2630%2Fab8aac

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