A team being headed up by researchers from the Australian National University (ANU) is developing quantum memory that stores information in the form of light. The process that the ANU Research School of Physics and Engineering has pioneered using a medium comprised of a praseodymium-doped yttrium orthosilicate crystal that stores light for later retrieval.
The crystal is cooled to three degrees Kelvin and held in an electrical field. The prepared yttrium orthosilicate crystal is able to absorb a light pulse which is held in place when the electrical field surrounding the quantum memory is flipped. Lead researcher Morgan Hedges explains that the light is held stationary within the crystal until it is released. The result on release is a three-dimensional hologram, “accurate right down to the last photon”.
Hedges outlined possible applications for the pioneering work saying, “Because of the inherent uncertainty in quantum mechanics, some of the information in this light will be lost the moment it is measured, making it a read-once hologram. Quantum mechanics guarantees this information can only be read once, making it perfect for secure communication”.
At present light can be stored in this manner for just over a second. The ANU-led team is now working on increasing that storage time to several hours.
Brett Venter
