Scientists in South Korea have created what they call “the world’s smallest ballgame” by throwing individual atoms between two light traps. This research may ultimately lead to more adaptive and dynamic quantum computers.
The ability to capture and manipulate individual atoms, particles, and even live bacteria using lasers was a Nobel Prize-winning breakthrough. The radiation pressure of light is powerful enough to move or hold microscale objects, and can create optical tweezers, traps, and even tractor beams.
For new research, researchers at the Korea Advanced Institute of Science and Technology (KAIST) have developed a method of throwing atoms from one trap to another. As is usual with this kind of setup, the team started by cooling clouds of rubidium atoms to near absolute zero, then confined them to a grid of lasers tuned to a wavelength of 800 nanometers.
To toss them, the team accelerates one light trap and turns it off to send the atoms flying. To catch it, turn on another trap and slow it down until it stops. In the test, the scientist threw an atom over a distance of 4.2 micrometers at a speed of up to 65 cm (26 inches) per second.
“Free-flying atoms move from one place to another without being held in or interacting with optical traps,” said Jaewook Ahn, the lead author of the study. “In other words, an atom is thrown and he is caught between two light traps, much like the ball moves between the pitcher and catcher in a baseball game.”
Interestingly, the research team showed that atoms can pass through other fixed optical traps without interfering or interacting with other atoms along the way. This means that it can be an effective technique for moving atoms around in an array without resetting the whole thing.
“We often encountered placement errors that resulted in defects in the array,” says Ahn. “We wanted to find a way to efficiently repair defective arrays without moving a large number of atoms, which could lead to even more defects.”
The technology could also be used to create more dynamic quantum computers, allowing qubits of information to relate to each other and move around. By then, the team plans to continue working to improve its success rate of creating free-flying atoms from about 94%.
A study was published in a journal optical.
Source: Optics via Phys.org
