Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > UCLA advance with new nanomaterials good news for next-generation electronic devices

Abstract:
Team controls conduction, surface states in topological insulator nanoribbons

By Wileen Wong Kromhout

UCLA advance with new nanomaterials good news for next-generation electronic devices

Los Angeles, CA | Posted on February 14th, 2011

In recent years, topological insulators have become one of the hottest topics in physics. These new materials act as both insulators and conductors, with their interior preventing the flow of electrical currents while their edges or surfaces allow the movement of a charge.

Perhaps most importantly, the surfaces of topological insulators enable the transport of spin-polarized electrons while preventing the "scattering" typically associated with power consumption, in which electrons deviate from their trajectory, resulting in dissipation.

Because of such characteristics, these materials hold great potential for use in future transistors, memory devices and magnetic sensors that are highly energy efficient and require less power.

In a study published today in Nature Nanotechnology, researchers from UCLA's Henry Samueli School of Engineering and Applied Science and from the materials division of Australia's University of Queensland show the promise of surface-conduction channels in topological insulator nanoribbons made of bismuth telluride and demonstrate that surface states in these nanoribbons are "tunable" — able to be turned on and off depending on the position of the Fermi level.

"Our finding enables a variety of opportunities in building potential new-generation, low-dissipation nanoelectronic and spintronic devices, from magnetic sensing to storage," said Kang L. Wang, the Raytheon Professor of Electrical Engineering at UCLA Engineering, whose team carried out the research.

Bismuth telluride is well known as a thermoelectric material and has also been predicted to be a three-dimensional topological insulator with robust and unique surface states. Recent experiments with bismuth telluride bulk materials have also suggested two-dimensional conduction channels originating from the surface states. But it has been a great challenge to modify surface conduction, because of dominant bulk contribution due to impurities and thermal excitations in such small-band-gap semiconductors.

The development of topological insulator nanoribbons has helped. With their large surface-to-volume ratios, these nanoribbons significantly enhance surface conditions and enable surface manipulation by external means.

Wang and his team used thin bismuth telluride nanoribbons as conducting channels in field-effect transistor structures. These rely on an electric field to control the Fermi level and hence the conductivity of a channel. The researchers were able to demonstrate for the first time the possibility of controlling surface states in topological insulator nanostructures.

"We have demonstrated a clear surface conduction by partially removing the bulk conduction using an external electric field," said Faxian Xiu, a UCLA staff research associate and lead author of the study. "By properly tuning the gate voltage, very high surface conduction was achieved, up to 51 percent, which represents the highest values in topological insulators."

"This research is very exciting because of the possibility to build nanodevices with a novel operating principle," said Wang, who is also associate director of the California NanoSystems Institute (CNSI) at UCLA. "Very similar to the development of graphene, the topological insulators could be made into high-speed transistors and ultra-high-sensitivity sensors."

The new findings shed light on the controllability of the surface spin states in topological insulator nanoribbons and demonstrate significant progress toward high surface electric conditions for practical device applications. The next step for Wang's team is to produce high-speed devices based on their discovery.

"The ideal scenario is to achieve 100 percent surface conduction with a complete insulating state in the bulk," Xiu said. "Based on the current work, we are targeting high-performance transistors with power consumption that is much less than the conventional complementary metal-oxide semiconductors (CMOS) technology used typically in today's electronics."

Study collaborators Jin Zou, a professor of materials engineering at the University of Queensland; Yong Wang, a Queensland International Fellow; and Zou's team at the division of materials at the University of Queensland contributed significantly to this work. A portion of the research was also done in Alexandros Shailos' lab at UCLA.

The study was funded by the Focus Center Research Program—Center on Functional Engineered Nano Architectonics (FENA) at UCLA Engineering; the U.S. Defense Advanced Research Projects Agency (DARPA); and the Australian Research Council. The research on topological insulators was pioneered by FENA's Shoucheng Zhang, a professor of physics at Stanford University.

####

About UCLA Henry Samueli School of Engineering and Applied Science
The UCLA Henry Samueli School of Engineering and Applied Science, established in 1945, offers 28 academic and professional degree programs and has an enrollment of almost 5,000 students. The school's distinguished faculty are leading research to address many of the critical challenges of the 21st century, including renewable energy, clean water, health care, wireless sensing and networking, and cyber-security. Ranked among the top 10 engineering schools at public universities nationwide, UCLA Engineering is home to seven multimillion-dollar interdisciplinary research centers in wireless sensor systems, nanoelectronics, nanomedicine, renewable energy, customized computing, and the smart grid, all funded by federal and private agencies.

For more information, please click here

Contacts:
Media Contacts
Wileen Wong Kromhout
(310) 206-0540

Copyright © UCLA Henry Samueli School of Engineering and Applied Science

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

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

Possible Futures

IBM Announces $3 Billion Research Initiative to Tackle Chip Grand Challenges for Cloud and Big Data Systems: Scientists and engineers to push limits of silicon technology to 7 nanometers and below and create post-silicon future July 10th, 2014

Virus structure inspires novel understanding of onion-like carbon nanoparticles April 10th, 2014

Local girl does good March 22nd, 2014

Surface Characteristics Influence Cellular Growth on Semiconductor Material March 12th, 2014

Academic/Education

Haydale Announces Collaboration Agreement with Swansea University’s Welsh Centre for Printing and Coatings (WCPC) July 12th, 2014

STFC takes delivery of the 100th Hitachi Tabletop SEM in the UK July 3rd, 2014

Innovation Management and the Emergence of the Nanobiotechnology Industry July 1st, 2014

Albany NanoCollege Faculty Member Selected as Editor-in-Chief of the Prestigious Journal of Electronic Materials July 1st, 2014

Spintronics

University of Illinois study advances limits for ultrafast nano-devices July 10th, 2014

Harnessing magnetic vortices for making nanoscale antennas: Scientists explore ways to synchronize spins for more powerful nanoscale electronic devices April 30th, 2014

Could Diamonds Be A Computer’s Best Friend? Landmark experiment reveals the precious gem’s potential in computing March 24th, 2014

Spintronic Thermoelectric Power Generators: A step towards energy efficient electronic devices March 21st, 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

Memory Technology

Rice's silicon oxide memories catch manufacturers' eye: Use of porous silicon oxide reduces forming voltage, improves manufacturability July 10th, 2014

University of Illinois study advances limits for ultrafast nano-devices July 10th, 2014

Leti to Present Technological Platforms Targeting Industry’s Needs for the Future at Semicon West Workshop: Presentation at STS Session to Focus on Leti Advanced Lithography Programs for 1x Nodes and on Silicon Photonics at TechXPot June 25th, 2014

6TH CEA-LETI WORKSHOP ON INNOVATIVE MEMORY TECHNOLOGIES includes invited talks by Infineon, IBM, Schlumberger, Thales, Cisco and STMicroelectronics: June 24 Event to Explore NVM Application Horizons from Automotive to Oil & Gas: Responses from Innovative Technologies & Design June 12th, 2014

Sensors

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

Compact Vibration Harvester Power Supply with Highest Efficiency Opens Door to “Fix-and-Forget” Sensor Nodes July 23rd, 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

Tiny laser sensor heightens bomb detection sensitivity July 19th, 2014

Nanoelectronics

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

A Crystal Wedding in the Nanocosmos July 23rd, 2014

3-D nanostructure could benefit nanoelectronics, gas storage: Rice U. researchers predict functional advantages of 3-D boron nitride July 15th, 2014

IBM Announces $3 Billion Research Initiative to Tackle Chip Grand Challenges for Cloud and Big Data Systems: Scientists and engineers to push limits of silicon technology to 7 nanometers and below and create post-silicon future July 10th, 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

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