Images stored in magnetised vapour
Scientists at the Joint Quantum Institute (JQI) of the National Institute of Standards and Technology (NIST) and the University of Maryland have taken storing data in the cloud to a whole new level by demonstrating that they can store visual images within quite an ethereal memory device – a thin vapour of rubidium atoms. They say the effort may prove helpful in creating memory for quantum computers.
The work builds on an approach developed at the Australian National University, where scientists showed that a rubidium vapour could be manipulated in interesting ways using magnetic fields and lasers.
The vapour is contained in a small tube and magnetised, and a laser pulse made up of multiple light frequencies is fired through the tube. The energy level of each rubidium atom changes depending on which frequency strikes it, and these changes within the vapour become a sort of fingerprint of the pulse's characteristics. If the field's orientation is flipped, a second pulse fired through the vapour takes on the exact characteristics of the first pulse – in essence, a readout of the fingerprint.
'With our paper, we've taken this same idea and applied it to storing an image – basically moving up from storing a single "pixel" of light information to about a hundred,' says Paul Lett, a physicist with JQI and NIST's Quantum Measurement Division.
'By modifying their technique, we have been able to store a simple image in the vapour and extract pieces of it at different times.'