Electrons squeezed into 'one-dimensional' wires yield quantum effects

CAMBRIDGE, Mass., Sept. 15 (UPI) -- Scientists have witnessed quantum effects in electrons after squeezing them into "one-dimensional" wires.

Researchers created so-called "quantum wires" out of the semiconducting material gallium arsenide. The wires were used to bridge the gaps between 6,000 narrow strips of metal. Scientists manipulated the magnetic field and voltage to narrow the available pathways across the bridges.

When the scientists squeezed the electrons onto the quantum wire bridges, they created a traffic jam -- triggering a wave-like quantum effect.

Researcher Christopher Ford likened this wave-like passage of subatomic information to the physics of an overcrowded trolley car.

"If someone tries to get in a door, they have to push the people closest to them along a bit to make room," Ford, a researcher at the University of Cambridge's Cavendish Laboratory, explained in a news release. "In turn, those people push slightly on their neighbors, and so on."

"A wave of compression passes down the carriage, at some speed related to how people interact with their neighbors, and that speed probably depends on how hard they were shoved by the person getting on the train," Ford continued. "By measuring this speed, one could learn about the interactions."

But electrons don't just have directional momentum, they also have spin. Scientists were able to design the quantum wire to carry the energy of these quantum spin waves -- in addition to their charge waves.

Scientists have devised a variety of theoretical ideas about how quantum spin waves are passed across a chain of electrons. The latest research allowed scientists to test their theories. Their tests confirmed predictions that different interactions between quantum-mechanical particles would produce a hierarchy of different spin wave "modes" -- some stronger than others.

The tests also confirmed the prediction that the strongest spin waves would be measured across the shortest quantum wires.

Researchers believe their findings -- detailed in the journal Nature Communications -- will help scientists better understand the behavior of quantum-mechanical particles, and allow physicists to better control electrons in quantum computers.