Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > A 'nanoscale landscape' controls flow of surface electrons on a topological insulator: Stripe-like contours on a surface modulate electrons that behave like light

Abstract:
In the relatively new scientific frontier of topological insulators, theoretical and experimental physicists have been studying the surfaces of these unique materials for insights into the behavior of electrons that display some very un-electron-like properties.

A 'nanoscale landscape' controls flow of surface electrons on a topological insulator: Stripe-like contours on a surface modulate electrons that behave like light

Chestnut Hill, MA | Posted on October 25th, 2012

In topological insulators, electrons can behave more like photons, or particles of light. The hitch is that unlike photons, electrons have a mass that normally plays a defining role in their behavior. In the world of quantum physics, where everyday materials take on surprising and sometimes astonishing properties, electrons on the outer surface of these insulators behave and look uncharacteristically like light.

These unique properties have piqued the interests of scientists who see future applications in areas such as quantum computing and spintronics, or other realms rooted in the manipulation of electronic properties. The early challenge to those researchers is to begin to understand some simple ground rules for controlling these materials.

Boston College researchers report that the placement of tiny ripples on the surface of a topological insulator engineered from bismuth telluride effectively modulates so-called Dirac electrons so they flow in a pathway that perfectly mirrors the topography of the crystal's surface.

Associate Professor of Physics Vidya Madhavan and Assistant Professor of Physics Stephen Wilson report in the current online edition of Nature Communications that scanning tunneling microscopy is capable of revealing the characteristics of these tiny waves as they rise and fall, enabling the researchers to draw a direct connection between the features of the ripples and modulation of the waves across the material's surface.

Instead of chaotic behavior, the electrons flow in a path that mirrors the metal composite's surface, the team reports in an articled titled "Ripple-modulated electronic structure of a 3D topological insulator."

"What we've discovered is that electrons respond beautifully to this buckling of the material's surface," said Madhavan, the project director.

So harmoniously do the waves flow across the ripples - placed approximately 100 nanometers apart - that the researchers say further modifications of the crystal's "nanoscale landscape" could produce enough control to produce a one-dimensional quantum wire capable of carrying current with no dissipation.

The rippled surface appears to exert greater control and run less risk of creating imperfections than other methods, such as introducing chemical dopants, used in attempts to modulate the flow of electrons on the surface of other topological insulators, the researchers found.

Madhavan said the team had to provoke the electrons, which lay placidly atop the surface-state of the insulator, much like the glassy surface of an undisturbed lake. The team disrupted the electrons by introducing impurities, which had an effect similar to that of dropping a stone in a calm lake. This provocation produced waves of electrons that behave like waves of light as they travel pathways that mirror the contours created in the crystal.

"We did not expect the electrons to follow the topography," said Madhavan. "The topography imposes a sinusoidal potential upon the waves. The ripples create that potential by giving the electrons a landscape to follow. This is a way of possibly manipulating these electrons in topological insulators."

In addition to Madhavan and Wilson, the project team included post-doctoral researcher Yoshinori Okada and graduate students Wenwen Zhou, Daniel Walkup and Chetan Dhital.

NOTE: The report "Ripple-modulated electronic structure of a 3D topological insulator" can be cited via a digital object identifier (DOI) number. The DOI for this article is 10.1038/ncomms2150.

####

For more information, please click here

Contacts:
Ed Hayward

617-552-4826

Copyright © Boston College

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

Virginia Tech physicists propose path to faster, more flexible robots: Virginia Tech physicists revealed a microscopic phenomenon that could greatly improve the performance of soft devices, such as agile flexible robots or microscopic capsules for drug delivery May 17th, 2024

Gene therapy relieves back pain, repairs damaged disc in mice: Study suggests nanocarriers loaded with DNA could replace opioids May 17th, 2024

Shedding light on perovskite hydrides using a new deposition technique: Researchers develop a methodology to grow single-crystal perovskite hydrides, enabling accurate hydride conductivity measurements May 17th, 2024

Oscillating paramagnetic Meissner effect and Berezinskii-Kosterlitz-Thouless transition in cuprate superconductor May 17th, 2024

Spintronics

Researchers discover a potential application of unwanted electronic noise in semiconductors: Random telegraph noises in vanadium-doped tungsten diselenide can be tuned with voltage polarity August 11th, 2023

Quantum materials: Electron spin measured for the first time June 9th, 2023

Rensselaer researcher uses artificial intelligence to discover new materials for advanced computing Trevor Rhone uses AI to identify two-dimensional van der Waals magnets May 12th, 2023

Spin photonics to move forward with new anapole probe November 4th, 2022

Chip Technology

Diamond glitter: A play of colors with artificial DNA crystals May 17th, 2024

Oscillating paramagnetic Meissner effect and Berezinskii-Kosterlitz-Thouless transition in cuprate superconductor May 17th, 2024

Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024

Utilizing palladium for addressing contact issues of buried oxide thin film transistors April 5th, 2024

Quantum Computing

Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024

Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024

With VECSELs towards the quantum internet Fraunhofer: IAF achieves record output power with VECSEL for quantum frequency converters April 5th, 2024

Chemical reactions can scramble quantum information as well as black holes April 5th, 2024

Discoveries

Virginia Tech physicists propose path to faster, more flexible robots: Virginia Tech physicists revealed a microscopic phenomenon that could greatly improve the performance of soft devices, such as agile flexible robots or microscopic capsules for drug delivery May 17th, 2024

Diamond glitter: A play of colors with artificial DNA crystals May 17th, 2024

Finding quantum order in chaos May 17th, 2024

Advances in priming B cell immunity against HIV pave the way to future HIV vaccines, shows quartet of new studies May 17th, 2024

Announcements

Virginia Tech physicists propose path to faster, more flexible robots: Virginia Tech physicists revealed a microscopic phenomenon that could greatly improve the performance of soft devices, such as agile flexible robots or microscopic capsules for drug delivery May 17th, 2024

Diamond glitter: A play of colors with artificial DNA crystals May 17th, 2024

Finding quantum order in chaos May 17th, 2024

Oscillating paramagnetic Meissner effect and Berezinskii-Kosterlitz-Thouless transition in cuprate superconductor May 17th, 2024

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




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project