Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > RUB Physicists get into a SPIN again

Torkeln der Elektronenspins
 
The diagrams show how the spin wavers (oscillation shown at top) in relation to time following an alignment laser pulse. One oscillation period corresponds to one complete waver rotation. As anticipated, the strength (amplitude) of all red curves decreases with time. After 1.2 nanoseconds (ns) a laser control pulse is irradiated to suddenly change the alignment of the spin, indicated by the phase of blue and finally green curves: It is precisely the counter-phase to the black curve at the bottom, recorded without control pulse. Moreover this waver builds up in the counter-phase at 2.4 ns, so that the signal is particularly high here, significantly facilitating readout.
Torkeln der Elektronenspins

The diagrams show how the spin wavers (oscillation shown at top) in relation to time following an alignment laser pulse. One oscillation period corresponds to one complete waver rotation. As anticipated, the strength (amplitude) of all red curves decreases with time. After 1.2 nanoseconds (ns) a laser control pulse is irradiated to suddenly change the alignment of the spin, indicated by the phase of blue and finally green curves: It is precisely the counter-phase to the black curve at the bottom, recorded without control pulse. Moreover this waver builds up in the counter-phase at 2.4 ns, so that the signal is particularly high here, significantly facilitating readout.

Abstract:
The intrinsic rotation of electrons - the "spin" - remains unused by modern electronics. If use as an information carrier were possible, the processing power of electronic components would suddenly increase to a multiple of the present capacity. In cooperation with colleagues from Dortmund, St. Petersburg and Washington, Bochum physicists have now succeeded in aligning electron spin, bringing it to a controlled "waver" and reading it out.

RUB Physicists get into a SPIN again

Bochum, Germany | Posted on March 30th, 2009

The electron spin can also be realigned as required at any time using optical pulses. "This is the first, important step toward addressing these "quantum bits", which will form an integral part of data transfer systems and processors in the future", exclaimed Prof. Andreas Wieck. The researchers have published their report in NATURE Physics.

Complex Calculations in Minimum Space

The entirety of present day electronics is based on electrical charges: If a memory cell (bit) has an electrical charge, it represents a logical "1", if no charge is present this is a logical "0". However electrons have more than just a charge - they spin like a top around their own axis, producing a magnetic field, similar to the earth. This spin can be accelerated or decelerated by applying an external magnetic field. The "top" begins to waver and its axis tips to virtually any desired angle. If these manifold possibilities were used as information carriers, it would be possible to store a great deal more information than just "0" and "1" with an electron. Moreover adjacent electrons could be moved into various configurations, because they exert forces on one another in the same manner as two magnets on a bulletin board. This phenomenon would provide a significantly more complex base for data storage and processing. Even a small quantity of these so-call quantum bits (qubits), would allow extremely complex calculations, for which millions of bits are required today.

Confinement of Spins in Indium-Arsenic Islands

Naturally one single electron has only a very small measureable effect. For this reason individual electron measurements can only be performed with great difficulty using highly sensitive instruments. This is why the international research team has specialized in confining nearly one million electrons each in virtually identical indium-arsenic islands ("quantum dots") and totaling their effect. These "ensemble" measurements provide signals which are stronger by a magnitude of six, making them very sturdy and allowing them to be recorded easily. "Contrary to the preconceptions of many international competitors, all associated electron spins exhibit precisely the same behavior and the microscopic effects can therefore be measured very easily" stated Wieck.

Optical Switching of Quantum Dots

In the study published in "NATURE" the physicists were not only successful in aligning the electron spin; they also managed to rotate it optically using a laser pulse in any desired direction at any time and read this direction out with a further laser pulse. This is the first important step towards "addressing" and influencing qubits. "The interesting factor here is that these electrons are enclosed in solid bodies, so we no longer need complex high vacuum equipment and light occlusion on all sides to keep them permanently in a module as in quantum optics " stressed Prof. Wieck. In Bochum the extremely high vacuum is required only once during production of the quantum dot; after that the semiconductor system is sealed against air ingress, has a long service life and is just as reliable as all transistors and memory cells already in use today.

####

About Ruhr University in Bochum
From local best to international research excellence: The Ruhr-Universität Bochum (RUB) has character and charm; and its people make the campus a living and unique place. Discover a university with a profile, with interesting people, a one-off campus, and impressive numbers and facts.

Contacts:
Prof. Dr. Andreas Wieck
Chair for Applied Solid State Physics at the Ruhr University in Bochum
Tel.: 0234/32-28786

Copyright © Ruhr University in Bochum

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

Atom-thick CCD could capture images: Rice University scientists develop two-dimensional, light-sensitive material December 20th, 2014

Oregon researchers glimpse pathway of sunlight to electricity: Collaboration with Lund University uses modified UO spectroscopy equipment to study 'maze' of connections in photoactive quantum dots December 19th, 2014

Instant-start computers possible with new breakthrough December 19th, 2014

Aculon Hires New Business Development Director December 19th, 2014

Possible Futures

A novel method for identifying the body’s ‘noisiest’ networks November 19th, 2014

Researchers discern the shapes of high-order Brownian motions November 17th, 2014

VDMA Electronics Production Equipment: Growth track for 2014 and 2015 confirmed: Business climate survey shows robust industry sector November 14th, 2014

Open Materials Development Will Be Key for HP's Success in 3D Printing: HP can make a big splash in 3D printing, but it needs to shore up technology claims and avoid the temptation of the razor/razor blade business model in order to flourish November 11th, 2014

Spintronics

Switching to spintronics: Berkeley Lab reports on electric field switching of ferromagnetism at room temp December 17th, 2014

Pb islands in a sea of graphene magnetise the material of the future December 16th, 2014

'Giant' charge density disturbances discovered in nanomaterials: Juelich researchers amplify Friedel oscillations in thin metallic films November 26th, 2014

Researchers create & control spin waves, lifting prospects for enhanced info processing November 17th, 2014

Quantum Computing

Nanoscale resistors for quantum devices: The electrical characteristics of new thin-film chromium oxide resistors that can be tuned by controlling the oxygen content detailed in the 'Journal of Applied Physics' December 9th, 2014

Electron pairs on demand: Controlled emission and spatial splitting of electron pairs demonstrated December 4th, 2014

Graphene layer reads optical information from nanodiamonds electronically: Possible read head for quantum computers December 1st, 2014

University of Minnesota engineers make sound loud enough to bend light on a computer chip: Device could improve wireless communications systems November 28th, 2014

Nanoelectronics

Stacking two-dimensional materials may lower cost of semiconductor devices December 11th, 2014

Defects are perfect in laser-induced graphene: Rice University lab discovers simple way to make material for energy storage, electronics December 10th, 2014

Nanoscale resistors for quantum devices: The electrical characteristics of new thin-film chromium oxide resistors that can be tuned by controlling the oxygen content detailed in the 'Journal of Applied Physics' December 9th, 2014

'Giant' charge density disturbances discovered in nanomaterials: Juelich researchers amplify Friedel oscillations in thin metallic films November 26th, 2014

Quantum nanoscience

Fraud-proof credit card possible because of quantum physics December 16th, 2014

Nanoscale resistors for quantum devices: The electrical characteristics of new thin-film chromium oxide resistors that can be tuned by controlling the oxygen content detailed in the 'Journal of Applied Physics' December 9th, 2014

High photosensitivity 2D-few-layered molybdenum diselenide phototransistors December 8th, 2014

Electron pairs on demand: Controlled emission and spatial splitting of electron pairs demonstrated December 4th, 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