Lasers have been used for the first time to throw and trap individual atoms of extreme cold . This technique could be used in the future to assemble quantum computers.

atoms that are nearly as cold as absolute zero into different formations, researchers typically grab and move them with highly focused laser beams called optical tweezers . Ahn Jae-woo of the Korea Advanced Institute of Science and Technology and his colleagues wanted to find a way to minimize the amount of time optical tweezers are in contact with atoms , since laser light can disturb some properties of atoms .

They started with a small metal and glass box filled with rubidium atoms , which are 40 millionths of a degree above absolute zero . Such ultracold atoms are very sensitive to the electromagnetic force that light exerts on them. The team used this property to deliver an optical shock to the atoms , effectively tuning the laser light to speed the atoms toward their destination. Then, another pair of optical tweezers was turned on , trapping the atom and slowing it down until it stopped at the desired location 12.6 micrometers away.

it easier to build larger (and therefore more powerful) quantum computers using ultracold atoms . In these computers, each ultracold atom stores information, and they are all arranged in a tight grid so that they can process that information by interacting with neighboring atoms through electromagnetic forces. Throwing the atoms into place could also be a way to quickly reorganize the mesh if a mistake occurs and the atoms need to be replaced or moved, he said .

atom in the middle of the array,” said Mark Safman of the University of Wisconsin-Madison . “Typically, you have to move the optical tweezers through many points in the array, which can disturb the atoms at those positions.” .If you can throw the atoms to the center, the problem is solved.”

In the experiments, some atoms fell off or were not captured successfully, so the new method still needs to be refined, Safman said .