Atomic baseball? Scientists play catch with a single atom in new study

For the first time, scientists have shown they can throw and catch individual atoms using light.

The researchers achieved the impressive milestone by using optical traps, which use a highly focused laser beam capable of manipulating tiny objects.

Their experiment could help build the next generation of quantum computers.

A flying atom experiment

In a world first, the group of scientists released an atom from an optical trap and caught it in another trap.

"The freely flying atoms move from one place to the other without being held by or interacting with the optical trap," research team member Jaewook Ahn from the Korea Advanced Institute of Science and Technology explained in a press statement. "In other words, the atom is thrown and caught between the two optical traps much like the ball travels between the pitcher and a catcher in a baseball game."

The researchers, who published their findings in a new paper in the journal Optica, detail how they threw chilled rubidium atoms over a distance of 4.2 micrometers and at a speed of up to 65 centimeters per second.

The new research could help in the development of quantum computers, which use quirks of quantum physics, including superposition, to solve problems that would require classical computers thousands of years.

"These types of flying atoms could enable a new type of dynamic quantum computing by allowing the relative locations of qubits — the quantum equivalent to binary bits — to be more freely changed," Ahn explained.

"It could also be used to create collisions between individual atoms, opening a new field of atom-by-atom chemistry."

The race for quantum supremacy

The new research forms a part of the ongoing goal to build functional quantum computers using the optical traps used in the new experiment.

Quantum physicists use these traps to arrange atoms in a particular order for quantum computing applications.

“We often encountered arrangement errors that rendered an array defective,” said Ahn. “We wanted to find an efficient way to fix a defective array without having to move a large number of atoms, because that could result in even more defects.”

For their experiments, the researchers chilled rubidium atoms to almost 0 K (near absolute zero of temperature). They then used optical traps with an 800 nm laser. In order to throw an atom, they accelerated the optical trap holding the atom and then turned the trap off, causing the atom to launch outward.

To catch the wayward atom, they then turned on another trap, which decelerates the atom until it stops completely. Using this method, the scientists created free-flying atoms roughly 94 percent of the time. Next, they aim to boost that success rate to roughly 100 percent.