A team from the National Institute of Standards and Technology has successfully stored two frames of a simple "movie" in a cloud of rubidium gas for the first time. Atomic storage is one vital aspect of quantum networks, and rubidium vapor has been one of the most promising media. First, images are encoded in photons and sent into a cloud of rubidium atoms. Then, a magnetic field is turned on, causing the atoms to absorb the photons. When it's switched off again, the photons — and their information — are emitted.

Using this technique, the group encoded and stored images of two letters in the cloud. When the information was released, it was recorded by a high-speed camera, "allowing the storage of a short movie in an atomic memory." The images play back opposite to the order in which they were encoded, so it essentially runs backward, but this is still the first proof that multiple images can be stored and retrieved at different times in non-solid media. The paper will be published in an upcoming issue of Optics Express.