Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > How the alphabet of data processing is growing: Research team generates flying 'qubits' - Nature Nanotechnology: On the way to the quantum computer

Electron one-way street
In this dual channel, electrons (blue) move on defined, parallel paths. Only one single electron fits through at a time. By means of tunnel coupling, the electron can switch back and forth between the channels, thus occupying two different states, which are denoted by “arrow up” and “arrow down”. The electron virtually flies in both tracks at the same time, its two states overlap.

© Andreas Wieck
Electron one-way street In this dual channel, electrons (blue) move on defined, parallel paths. Only one single electron fits through at a time. By means of tunnel coupling, the electron can switch back and forth between the channels, thus occupying two different states, which are denoted by “arrow up” and “arrow down”. The electron virtually flies in both tracks at the same time, its two states overlap.

© Andreas Wieck

Abstract:
The alphabet of data processing could include more elements than the "0" and "1" in future. An international research team has achieved a new kind of bit with single electrons, called quantum bits, or qubits. With them, considerably more than two states can be defined. So far, quantum bits have only existed in relatively large vacuum chambers. The team has now generated them in semiconductors. They have put an effect in practice, which the RUB physicist Prof. Dr. Andreas Wieck had already theoretically predicted 22 years ago. This represents another step along the path to quantum computing. Together with colleagues from Grenoble and Tokyo, Wieck from the Chair of Applied Solid State Physics reports on the results in the journal Nature Nanotechnology.

How the alphabet of data processing is growing: Research team generates flying 'qubits' - Nature Nanotechnology: On the way to the quantum computer

Bochum, Germany | Posted on March 21st, 2012

Conventional bits

The basic units of today's data processing are the bit states "0" and "1", which differ in their electrical voltage. To encode these states, only the charge of the electrons is crucial. "Electrons also have other properties though" says Wieck, and these are exactly what you need for quantum bits. "The extension from bits to quantum bits can dramatically increase the computational power of computers" says the physicist.

The new bit generation

A quantum bit corresponds to a single electron in a particular state. Together with his colleagues, Wieck used the trajectories of an electron through two closely spaced channels for encoding. In principle, two different states are possible: the electron either moves in the upper channel or in the lower channel - which would then only form a binary system again. According to quantum theory, however, a particle can be in several states simultaneously, that is, it can quasi fly through both channels at the same time. These overlapping states can form an extensive alphabet of data processing.

A recipe for qubits

In order to generate quantum bits with different states, the researchers allowed individual electrons to interfere with each other. This works with the so-called Aharonov-Bohm effect: powered by an external voltage, the electrons fly through a semiconducting solid. Within this solid, their trajectory is first forked and then reunited. Thus, each electron flies simultaneously on both possible paths. When the two paths come together again, there is interference, i.e., the two electron waves overlap and quantum bits with different overlapping states are generated.

Controlling electrons on defined paths

Normally, an electron wave moves through a solid body on many different paths at the same time. Due to impurities in the material, it loses its phase information and thus its ability to encode a particular state. To maintain the phase information, the researchers at the RUB grew a high-purity gallium arsenide crystal and used a dual channel proposed by Wieck more than 20 years ago.

How the dual channel works

An electron reaches the fork via two closely spaced channels. These are coupled with each other (tunnel-coupling), so that the electron flies simultaneously on two different paths. The phases of the electron waves are maintained by the coupling. The same dual channel was also used by the team after the electron waves were reunited at the end of the fork. In this way, they produced quantum bits with clear states which are suitable for encoding information. "Unfortunately, not all the electrons take part in this process, so far it's only a few percent" commented Wieck. "Some students in my department are, however, already working on growing crystals with higher electron densities".

Bibliographic record

M. Yamamoto, S. Takada, C. Bäuerle, K. Watanabe, A.D. Wieck, S. Tarucha (2012): Electrical control of a solid-state flying qubit, Nature Nanotechnology, doi: 10.1038/nnano.2012.28

Editor

Dr. Julia Weiler

####

For more information, please click here

Contacts:
Dr. Andreas Wieck
Chair of Applied Solid State Physics
Faculty of Physics and Astronomy at the Ruhr-Universität
44780 Bochum, Germany

49-234-322-8786

Copyright © Ruhr-University 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 Links

Earlier press release on this theme:

Related News Press

News and information

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

Iranian Scientists Use Nanotechnology to Increase Power, Energy of Supercapacitors December 18th, 2014

Chip Technology

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

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

Stanford team combines logic, memory to build a 'high-rise' chip: Today circuit cards are laid out like single-story towns; Futuristic architecture builds layers of logic and memory into skyscraper chips that would be smaller, faster, cheaper -- and taller December 15th, 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

Discoveries

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

Creation of 'Rocker' protein opens way for new smart molecules in medicine, other fields December 18th, 2014

Iranian Scientists Use Nanotechnology to Increase Power, Energy of Supercapacitors December 18th, 2014

Announcements

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

Iranian Scientists Use Nanotechnology to Increase Power, Energy of Supercapacitors December 18th, 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