Quantum computers of the future will likely communicate via light. An atom stores information, and a photon carries it across the network. But an atom doesn't hang still: it jitters and oscillates, and this motion can corrupt the signal.
Previously, engineers could only calculate for a stationary atom. The authors of the new work have, for the first time, built a complete theory that accounts for atomic jitter. They derived a simple equation — a kind of "translator" between atomic motion and the state of the reflected photon. It turns out that the effect depends on how the atom is held — in what kind of "trap."
Now one can calculate in advance under what conditions motion won't spoil a quantum gate — a basic operation, like addition in a regular computer. And in the future, one might even use the motion itself as a useful resource, for example, to encode additional information.
The jitter of an atom in a trap is like the vibration of a guitar string: it has its own frequencies and amplitudes that can be precisely measured and controlled.