Like regular (classical) computers, quantum computers must be able to receive, store, and manipulate information in order to perform calculations. But the fragile nature of quantum information—which exists as a "0" or "1" or both simultaneously—poses challenges. In research published March 14 in the journal Nature, Yale physicists report an advance in developing memory mechanisms. The advance involves photons, the smallest units of microwave signals, which can serve as a quantum computer's memory, like the RAM of a regular computer. Photons can carry and hold quantum information for a long time, because they interact weakly with the media they typically travel through—coaxial cables, wires, or air, for example. The weakness of these interactions prevents the photons from being absorbed by the medium and preserves the quantum information, once it's been encoded.
Via Szabolcs Kósa