Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > 'Science:' Novel quantum effect directly observed and explained

Abstract:
Research team succeeds in observing electrons in the quantum spin Hall state; Material suitable for spin sources and quantum computing in information processing

'Science:' Novel quantum effect directly observed and explained

Germany | Posted on February 12th, 2009

An international research team has succeeded in gaining an in-depth insight into an unusual phenomenon, as reported in the current edition of the high-impact journal "Science". The researchers succeeded for the first time in directly measuring the spin of electrons in a material that exhibits the quantum spin Hall effect, which was theoretically predicted in 2004 and first observed in 2007. Astonishingly, the spin currents flow without any external stimulus as a result of the internal structure of the material. The flow of information is loss-free, even for slight irregularities. This paves the way towards fault-tolerant quantum computers and towards a source of spin currents.

The spin is a quantum-mechanical property of elementary particles and as a rule it occurs in two variations. This is what makes it suitable for use as a binary information carrier. In hard disk drives, for example, spins are already being used to store digital information.

In 2007, physicists from Germany and the USA observed a new phenomenon that could make it possible to transport and electrically manipulate information in future storage media almost loss-free - the quantum spin Hall effect. The discovery was hailed by the high-impact journal "Science" as one of the ten most important scientific breakthroughs of 2007.

The first study that succeeded in directly observing the spin of flowing particles was published this week in "Science" by an international research team, which included Dr. Gustav Bihlmayer from Forschungszentrum Jülich, member of the Helmholtz Association. Until now, the quantum spin Hall effect could only be indirectly proven.

"We were able to show for the first time that two spin currents flow in opposite directions in the edge region of an alloy of bismuth and antimony. An external energy supply is not required; losses cannot occur," explained Dr. Gustav Bihlmayer from the Jülich Institute of Solid State Research. The causes of this astonishing phenomenon are interactions within the material. Of particular interest to materials scientists is the fact that imperfections in the material do not impair the spin currents. "This means that materials known as topological materials have spin currents that can be manipulated electrically and are therefore suitable for use as spin sources. They could even pave the way towards fault-tolerant quantum computers," said Bihlmayer. "Our process will make it possible to test the suitability of materials for this purpose in the future."

The current study makes use of theoretical calculations and photoelectron spectroscopy. The photons in a synchrotron beam cause electrons to be emitted from the material surface. The energy and momentum distribution, as well as the spin of the particles, can be used to derive concrete information on the occurrence of the quantum spin Hall effect. Previous methods were based on measurements of the conductivity in the materials at variable voltages.

Spins for data processing

Spins are a hot topic in research. Physicists and nanoelectricians have high hopes for what is known as spin electronics. Spin electronics does not just exploit the electric charge of electrons and nuclei but also their spin, and should therefore lead to the development of new approaches for the processing and coding of information in information processing. Faster, smaller and more energy-efficient computers could thus become a reality, as could completely new components capable of performing a number of different functions such as storage, logic and communication. One of the most prominent ideas is that of the quantum computer. For spin-electronic concepts, scientists conducting basic research are desperately searching for new materials and phenomena that will make it possible to control both spin orientation and spin flow.

Original publication
Science, 13 February 2009, vol. 323, issue 5916,
Observation of unconventional quantum spin textures in topologically ordered materials, D. Hsieh, Y. Xia, L. Wray, D. Qian, A. Pal, J.H. Dil, F. Meier, J. Osterwalder, G. Bihlmayer, C.L. Kane, Y.S. Hor, R.J. Cava, M.Z. Hasan

####

For more information, please click here

Contacts:
Erhard Lachmann

0049-246-161-1841

Copyright © Helmholtz Association of German Research Centres

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

Sandia researchers make solid ground toward better lithium-ion battery interfaces: Reducing the traffic jam in batteries December 13th, 2017

Perking up and crimping the 'bristles' of polyelectrolyte brushes December 13th, 2017

Columbia engineers create artificial graphene in a nanofabricated semiconductor structure: Researchers are the first to observe the electronic structure of graphene in an engineered semiconductor; finding could lead to progress in advanced optoelectronics and data processing December 13th, 2017

Leti to Demo Wristband with Embedded Sensors to Diagnose Sleep Apnea: APNEAband, Which Will Be Demonstrated at CES 2018, Also Monitors Mountain Sickness, Dehydration, Dialysis Treatment Response and Epileptic Seizures December 12th, 2017

Quantum Computing

Enhancing the quantum sensing capabilities of diamond: Shooting electrons at diamonds can introduce quantum sensors into them November 24th, 2017

Quantum optics allows us to abandon expensive lasers in spectroscopy: Lomonosov Moscow State University scientists have invented a new method of spectroscopy November 21st, 2017

Spin current detection in quantum materials unlocks potential for alternative electronics October 15th, 2017

Quantum manipulation power for quantum information processing gets a boost: Improving the efficiency of quantum heat engines involves reducing the number of photons in a cavity, ultimately impacting quantum manipulation power October 14th, 2017

Discoveries

Sandia researchers make solid ground toward better lithium-ion battery interfaces: Reducing the traffic jam in batteries December 13th, 2017

Perking up and crimping the 'bristles' of polyelectrolyte brushes December 13th, 2017

Columbia engineers create artificial graphene in a nanofabricated semiconductor structure: Researchers are the first to observe the electronic structure of graphene in an engineered semiconductor; finding could lead to progress in advanced optoelectronics and data processing December 13th, 2017

Untangling DNA: Researchers filter the entropy out of nanopore measurements December 8th, 2017

Announcements

Sandia researchers make solid ground toward better lithium-ion battery interfaces: Reducing the traffic jam in batteries December 13th, 2017

Perking up and crimping the 'bristles' of polyelectrolyte brushes December 13th, 2017

Columbia engineers create artificial graphene in a nanofabricated semiconductor structure: Researchers are the first to observe the electronic structure of graphene in an engineered semiconductor; finding could lead to progress in advanced optoelectronics and data processing December 13th, 2017

Leti to Demo Wristband with Embedded Sensors to Diagnose Sleep Apnea: APNEAband, Which Will Be Demonstrated at CES 2018, Also Monitors Mountain Sickness, Dehydration, Dialysis Treatment Response and Epileptic Seizures December 12th, 2017

Quantum nanoscience

Columbia engineers create artificial graphene in a nanofabricated semiconductor structure: Researchers are the first to observe the electronic structure of graphene in an engineered semiconductor; finding could lead to progress in advanced optoelectronics and data processing December 13th, 2017

Enhancing the quantum sensing capabilities of diamond: Shooting electrons at diamonds can introduce quantum sensors into them November 24th, 2017

Quantum optics allows us to abandon expensive lasers in spectroscopy: Lomonosov Moscow State University scientists have invented a new method of spectroscopy November 21st, 2017

'Find the Lady' in the quantum world: International team of researchers presents method for quantum-mechanical swapping of positions October 18th, 2017

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