Synchronized resistance to inhomogeneous magnetic field-induced dephasing of an image stored in a cold atomic ensemble

TL;DR

This paper demonstrates that applying a uniform magnetic field can synchronize atomic spins in a cold-atom memory, significantly reducing pattern distortion caused by magnetic inhomogeneities and enhancing storage longevity for quantum networks.

Contribution

It introduces a method to suppress magnetic field-induced dephasing in cold-atom memories by using a strong uniform magnetic field to synchronize atomic spins.

Findings

Magnetic inhomogeneity causes pattern distortion in atomic memory.

Applying a uniform magnetic field suppresses dephasing effects.

Enhanced pattern preservation over longer times achieved.

Abstract

Long-lived storage of arbitrary transverse multimodes is important for establishing a high-channel-capacity quantum network. Most of the pioneering works focused on atomic diffusion as the dominant impact on the retrieved pattern in an atom-based memory. In this work, we demonstrate that the unsynchronized Larmor precession of atoms in the inhomogeneous magnetic field dominates the distortion of the pattern stored in a cold-atom-based memory. We find that this distortion effect can be eliminated by applying a strong uniform polarization magnetic field. By preparing atoms in magnetically insensitive states, the destructive interference between different spin-wave components is diminished, and the stored localized patterns are synchronized further in a single spin-wave component; then, an obvious enhancement in preserving patterns for a long time is obtained. The reported results are very promising for studying transverse multimode decoherence in storage and high-dimensional quantum networks in the future.