Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > You can’t play nano-billiards on a bumpy table

False colour scanning electron microscope image: the 'table' is the central green square region. The 'pockets' are narrowings that join to open green areas. The 'cushion' is the grey trench that defines the device. White scale bar - 500 nanometres
False colour scanning electron microscope image: the 'table' is the central green square region. The 'pockets' are narrowings that join to open green areas. The 'cushion' is the grey trench that defines the device. White scale bar - 500 nanometres

Abstract:
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.

You can’t play nano-billiards on a bumpy table

Sydney, Australia | Posted on May 14th, 2012

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 only by the billiard table's shape (e.g. square, circular, stadium-shaped).

"We found that we can ‘reconfigure' the warping by warming the table up and cooling it down again, with the electron paths changing radically in response," says Professor Richard Taylor from the University of Oregon. "This shows that the warping is much more important than expected."

Using a new billiard design developed during PhD work at UNSW by lead author Dr Andrew See, the silicon dopants are removed, eliminating the associated warping, and enabling the electron paths to stay the same each time they cool the device down for study.

"These undoped billiard devices pinpoint the silicon dopants as the cause of the warping. The level of improvement obtained by removing the silicon was unexpected, earlier work on much larger devices suggested that we wouldn't see this level of improvement.

But at the nanoscale, the dopant atoms really do make a really big difference", says Micolich, "Ultimately, our work provides important insight into how to make better nanoscale electronic devices, ones where the properties are both more predictable, and more consistent each time we use them."

####

For more information, please click here

Contacts:
Bob Beale

61-411-705-435

Adam Micolich
02 9385 6132, 0408 479 432

Copyright © University of New South Wales

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Physics

Measuring the Smallest Magnets July 28th, 2014

News and information

Measuring the Smallest Magnets July 28th, 2014

WITec to host the 11th Confocal Raman Imaging Symposium from September 29th - October 1st in Ulm, Germany July 28th, 2014

FEI adds Phase Plate Technology and Titan Halo TEM to its Structural Biology Product Portfolio: New solutions provide the high-quality imaging and contrast necessary to analyze the 3D structure of molecules and molecular complexes July 28th, 2014

Production of Toxic Gas Sensor Based on Nanorods July 28th, 2014

Govt.-Legislation/Regulation/Funding/Policy

Seeing is bead-lieving: Rice University scientists create model 'bead-spring' chains with tunable properties July 28th, 2014

Stanford team achieves 'holy grail' of battery design: A stable lithium anode - Engineers use carbon nanospheres to protect lithium from the reactive and expansive problems that have restricted its use as an anode July 27th, 2014

New imaging agent provides better picture of the gut July 25th, 2014

A*STAR and industry form S$200M semiconductor R&D July 25th, 2014

Chip Technology

A*STAR and industry form S$200M semiconductor R&D July 25th, 2014

A Crystal Wedding in the Nanocosmos July 23rd, 2014

Nanometrics Announces Upcoming Investor Events July 22nd, 2014

Penn Study: Understanding Graphene’s Electrical Properties on an Atomic Level July 22nd, 2014

Discoveries

Seeing is bead-lieving: Rice University scientists create model 'bead-spring' chains with tunable properties July 28th, 2014

Measuring the Smallest Magnets July 28th, 2014

Production of Toxic Gas Sensor Based on Nanorods July 28th, 2014

Stanford team achieves 'holy grail' of battery design: A stable lithium anode - Engineers use carbon nanospheres to protect lithium from the reactive and expansive problems that have restricted its use as an anode July 27th, 2014

Announcements

Measuring the Smallest Magnets July 28th, 2014

WITec to host the 11th Confocal Raman Imaging Symposium from September 29th - October 1st in Ulm, Germany July 28th, 2014

FEI adds Phase Plate Technology and Titan Halo TEM to its Structural Biology Product Portfolio: New solutions provide the high-quality imaging and contrast necessary to analyze the 3D structure of molecules and molecular complexes July 28th, 2014

Production of Toxic Gas Sensor Based on Nanorods July 28th, 2014

Military

Production of Toxic Gas Sensor Based on Nanorods July 28th, 2014

New imaging agent provides better picture of the gut July 25th, 2014

Nano-sized Chip "Sniffs Out" Explosives Far Better than Trained Dogs: TAU researcher's groundbreaking sensor detects miniscule concentrations of hazardous materials in the air July 23rd, 2014

Carbyne morphs when stretched: Rice University calculations show carbon-atom chain would go metal to semiconductor July 21st, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE