In Quantum Computing Leap, Tiny Lasers Target Individual Atoms

Manipulating Individual Atoms With Tiny Lasers
American Institute of Physics

If we're ever going to create the next-gen quantum computers that promise to solve complex and difficult problems at super-fast speeds, first we'll need to a means to manipulate atoms individually. So researchers from Duke and the University of Wisconsin have figured out how to do exactly that. Collaborators from those universities have demonstrated a laser system that can aim and focus tiny bursts of light onto single atoms without affecting other neighboring particles.

One of the more promising approaches to quantum computing – that is, computers that use quantum mechanical phenomena like entanglement to perform operations – is to suspend atoms in electromagnetic fields and use lasers to manipulate their states to carry out computations. But doing so requires a high degree of precision; a laser must be able to focus in on a particular atom without disturbing the states of other atoms in the system.

Using focused micromirrors each just twice the diameter of a human hair, the new system was able to focus in on individual atoms in just a few microseconds, something like 1,000 times faster than other beam manipulators developed for optical switching. Not to mention, the did it without making a mess of the quantum system. Each laser pulse found its target – one of a group of five rubidium-87 atoms – without disturbing its neighbors, which were only about one-tenth of the diameter of a hair away.

Not only did each beam manage to find and manipulate its target, but each was able to manipulate the quantum properties of the atom – more or less demonstrating the key technical abilities needed to build a quantum computer. There's still plenty of work to be done on the scientific side before quantum computing replaces our current silicon computing scheme, but it's both impressive and encouraging to see that the tools that can make it happen are coming along nicely.