Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button


DHgate

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

Study reveals how herpes virus tricks the immune system February 5th, 2016

Hepatitis virus-like particles as potential cancer treatment February 5th, 2016

Organic crystals allow creating flexible electronic devices: The researchers from the Faculty of Physics of the Moscow State University have grown organic crystals that allow creating flexible electronic devices February 5th, 2016

Researchers discover new phase of boron nitride and a new way to create pure c-BN February 5th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Hepatitis virus-like particles as potential cancer treatment February 5th, 2016

Researchers discover new phase of boron nitride and a new way to create pure c-BN February 5th, 2016

Scientists guide gold nanoparticles to form 'diamond' superlattices: DNA scaffolds cage and coax nanoparticles into position to form crystalline arrangements that mimic the atomic structure of diamond February 4th, 2016

Polar vortices observed in ferroelectric: New state of matter holds promise for ultracompact data storage and processing February 4th, 2016

Possible Futures

Hepatitis virus-like particles as potential cancer treatment February 5th, 2016

Scientists guide gold nanoparticles to form 'diamond' superlattices: DNA scaffolds cage and coax nanoparticles into position to form crystalline arrangements that mimic the atomic structure of diamond February 4th, 2016

Using mathematics to improve human health February 3rd, 2016

Scientists have put a high precision blood assay into a simple test strip: Researchers have developed a new biosensor test system based on magnetic nanoparticles February 3rd, 2016

Academic/Education

COD Grad Begins Postdoctoral Fellow at Harvard University: Marsela Jorgolli's Passion for Physics Has Led to a Decade of Academic Research That Continues at Harvard University as a Postdoctoral Fellow February 2nd, 2016

Heriot-Watt's Institute of Photonics & Quantum Sciences uses the Deben Microtest 2 kN tensile stage to characterise ceramics and engineering plastics January 21st, 2016

Multiple uses for the JPK NanoWizard AFM system in the Smart Interfaces in Environmental Nanotechnology Group at the University of Illinois at Urbana-Champaign January 20th, 2016

BioSolar Extends Research Agreement With UCSB for Next Phase of Its Super Battery Technology: Development Effort to Continue Under the Supervision of Nobel Laureate, Dr. Alan Heeger January 13th, 2016

Spintronics

A highway for spin waves: Researchers in Dresden develop process for controlling innovative information media February 1st, 2016

Spin dynamics in an atomically thin semi-conductor February 1st, 2016

Bismuth-based nanoribbons show 'topological' transport, potential for new technologies January 22nd, 2016

First all-antiferromagnetic memory device could get digital data storage in a spin January 16th, 2016

Chip Technology

Organic crystals allow creating flexible electronic devices: The researchers from the Faculty of Physics of the Moscow State University have grown organic crystals that allow creating flexible electronic devices February 5th, 2016

Scientists guide gold nanoparticles to form 'diamond' superlattices: DNA scaffolds cage and coax nanoparticles into position to form crystalline arrangements that mimic the atomic structure of diamond February 4th, 2016

Polar vortices observed in ferroelectric: New state of matter holds promise for ultracompact data storage and processing February 4th, 2016

Electrons and liquid helium advance understanding of zero-resistance: Study of electrons on liquid helium systems sheds light on zero-resistance phenomenon in semiconductors February 2nd, 2016

Memory Technology

A step towards keeping up with Moore's Law: POSTECH researchers develop a novel and efficient fabrication technology for cross-shaped memristor January 30th, 2016

Scientists build a neural network using plastic memristors: A group of Russian and Italian scientists have created a neural network based on polymeric memristors -- devices that can potentially be used to build fundamentally new computers January 28th, 2016

LC.300 Series Nanopositioning Controller from nPoint January 28th, 2016

First all-antiferromagnetic memory device could get digital data storage in a spin January 16th, 2016

Sensors

Scientists have put a high precision blood assay into a simple test strip: Researchers have developed a new biosensor test system based on magnetic nanoparticles February 3rd, 2016

Nanosheet growth technique could revolutionize nanomaterial production February 1st, 2016

New record in nanoelectronics at ultralow temperatures January 28th, 2016

NBC LEARN DEBUTS SIX-PART VIDEO SERIES, “NANOTECHNOLOGY: SUPER SMALL SCIENCE” Produced by NBC Learn in partnership with the National Science Foundation, and narrated by NBC News/MSNBC’s Kate Snow, series highlights leading research in nanotechnology January 25th, 2016

Nanoelectronics

Cornell researchers create first self-assembled superconductor February 1st, 2016

Spin dynamics in an atomically thin semi-conductor February 1st, 2016

New type of nanowires, built with natural gas heating: UNIST research team developed a new simple nanowire manufacturing technique February 1st, 2016

Nanosheet growth technique could revolutionize nanomaterial production February 1st, 2016

Announcements

Study reveals how herpes virus tricks the immune system February 5th, 2016

Hepatitis virus-like particles as potential cancer treatment February 5th, 2016

Organic crystals allow creating flexible electronic devices: The researchers from the Faculty of Physics of the Moscow State University have grown organic crystals that allow creating flexible electronic devices February 5th, 2016

Researchers discover new phase of boron nitride and a new way to create pure c-BN February 5th, 2016

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







Car Brands
Buy website traffic