There's nothing worse than a shonky pool table with an unseen groove or bump that sends your shot off course: a new study has found that the same goes at the nano-scale, where the "billiard balls" are tiny electrons moving across a "table" made of the semiconductor gallium arsenide.
These tiny billiard tables are of interest towards the development of future computing technologies. In a research paper titled "The Impact of Small-Angle Scattering on Ballistic Transport in Quantum Dots", an international team of physicists has shown that in this game of "semiconductor billiards", small bumps have an unexpectedly large effect on the paths that electrons follow.
Better still, the team has come up with a major redesign that allows these bumps to be ironed out. The study, led by researchers from the UNSW School of Physics, is published in the journal Physical Review Letters.
The team included colleagues, from the University of Oregon (US), Niels Bohr Institute (Denmark) and Cambridge University (UK).
"Scaled down a million-fold from the local bar variety, these microscopic pool tables are cooled to just above absolute zero to study fundamental science, for example, how classical chaos theory works in the quantum mechanical limit, as well as questions with useful application, such as how the wave-like nature of the electron affects how transistors work," says team member Associate Professor Adam Micolich. "In doing this, impurities and defects in the semiconductor present a serious challenge."
Ultra-clean materials are used to eliminate impurities causing backscattering (akin to leaving a glass on the billiard table) but until now has been no way to avoid the ionized silicon atoms that supply the electrons.
"Their electrostatic effect is more subtle, essentially warping the table's surface." explains Micolich.
Earlier studies assumed this warping was negligible, with the electron paths determined on
|Contact: Bob Beale|
University of New South Wales