Dual-rail optical gradient echo memory

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.

8 pages, 4 figures

References in corpus (6)

• Unconditional Room Temperature Quantum Memory
• Photon echoes generated by reversing magnetic field gradients in a rubidium vapour
• Quantum storage of polarization qubits in birefringent and anisotropically absorbing materials
• Continuous-Variable Quantum Computing in Optical Time-Frequency Modes using Quantum Memories
• Matched Slow Pulses Using Double Electromagnetically Induced Transparency
• Electromagnetically induced transparency and four-wave mixing in a cold atomic ensemble with large optical depth

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