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Have you ever tried to catch a speck of dust between your fingers? That’s challenging enough, but what about catching a single atom?

Controlling the position of individual atoms is vital for quantum computers, which use individual atoms as “qubits” – the quantum version of the “bits” of regular computers.

Usually atom assembly is a painstaking process, and can only be done one at a time.

In a new paper uploaded to the Arxiv (prior to peer review), physicists at Harvard, Caltech and MIT have teamed up to manipulate up to 50 individual rubidium atoms using an array of 100 optical tweezers.

The technique works a bit like the tractor beam from Star Trek. The atoms float around in a cloud within a vacuum chamber, and the tweezers pluck them out of mid-air (or, perhaps we should say, out of mid-vacuum).

The system then automatically arranges the atoms into a precise formation in less than half a second.

Optical tweezers are tightly focused beams of light able to hold microscopic particles, or even single atoms, in three dimensions. It works by focusing two laser beams on to the same spot.

An atom caught in the crossbeam stops dead, like a deer in headlights, because it is attracted to the strong electric field right at the center of the beam.

When the beam is moved, the atom is dragged with it.

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