Researchers demonstrate storage and retrieval of single photons

December 8, 2005, Atlanta, GA--In one of three papers published the December 8 issue of Nature, a group of physicists from the Georgia Institute of Technology led by Professors Alex Kuzmich and Brian Kennedy describe the storage and retrieval of single photons transmitted between remote quantum memories composed of rubidium atoms. The work represents a significant step toward quantum communication and computation networks that would store and process information using both photons and atoms. But the researchers caution that even with their rudimentary network operation, practical applications for quantum networking remain a long way off.

"The controlled transfer of single quanta between remote quantum memories is an important step toward distributed quantum networks," said Alex Kuzmich, the Cullen-Peck Assistant Professor in Georgia Tech's School of Physics. "But this is still a building block. It will take a lot of steps and several more years for this to happen in a practical way."

From an applications perspective, the storage and retrieval of a qubit state in an atomic quantum memory node is an important step towards a "quantum repeater." Such a device would be necessary for transmitting quantum information long distances through optical fibers.

Existing telecommunications networks use classical light to transmit information through optical fibers. To carry information long distances, such signals must be periodically boosted by repeater stations that cannot be used for quantum networking.