Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

University of Cincinnati researchers create all-electric spintronics

28.10.2009
Multidisciplinary team of UC researchers first to find an innovative and novel way to control an electron’s spin orientation using purely electrical means

A multidisciplinary team of UC researchers is the first to find an innovative and novel way to control an electron's spin orientation using purely electrical means.

Their findings were recently published in the prestigious, high-profile journal "Nature Nanotechnology," in an article titled "All-Electric Quantum Point Contact Spin-Polarizer."

For decades, the transistors inside radios, televisions and other everyday electronic items have transmitted data by controlling the movement of the charge of an electron. Scientists have since discovered that transistors that function by controlling an electron's spin instead of its charge would use less energy, generate less heat and operate at higher speeds. This has resulted in a new field of research — spin electronics or spintronics — that offers one of the most promising paradigms for the development of novel devices for use in the post-CMOS (complementary metal–oxide–semiconductor) era.

Until now, scientists have attempted to develop spin transistors by incorporating local ferromagnets into device architectures. This results in significant design complexities, especially in view of the rising demand for smaller and smaller transistors," says Philippe Debray, research professor in the Department of Physics in the McMicken College of Arts & Sciences. "A far better and practical way to manipulate the orientation of an electron's spin would be by using purely electrical means, like the switching on and off of an electrical voltage. This will be spintronics without ferromagnetism or all-electric spintronics, the holy grail of semiconductor spintronics."

The team of researchers led by Debray and Professor Marc Cahay (Department of Electrical and Computer Engineering) is the first to find an innovative and novel way to control an electron's spin orientation using purely electrical means.

"We used a quantum point contact — a short quantum wire — made from the semiconductor indium arsenide to generate strongly spin-polarized current by tuning the potential confinement of the wire by bias voltages of the gates that create it," Debray says.

In the diagram at left, (Left) Scanning electron micrograph of the quantum point contact schematically illustrates unpolarized (spin up and spin down) electrons incident on the left coming out of the device spin-polarized with spin up. (Right) Spatial distribution of spin polarization in the quantum point contact constriction.

Debray continues, "The key condition for the success of the experiment is that the potential confinement of the wire must be asymmetric — the transverse opposite edges of the quantum point contact must be asymmetrical. This was achieved by tuning the gate voltages. This asymmetry allows the electrons — thanks to relativistic effects — to interact with their surroundings via spin-orbit coupling and be polarized. The coupling triggers the spin polarization and the Coulomb electron–electron interaction enhances it."

Controlling spin electronically has major implications for the future development of spin devices. The work by Debray's team is the first step. The next experimental step would be to achieve the same results at a higher temperature using a different material such as gallium arsenide.

This work was supported by National Science Foundation awards ECCS 0725404 and DMR 0710581.

Wendy Beckman | EurekAlert!
Further information:
http://www.uc.edu

More articles from Interdisciplinary Research:

nachricht 36 big data research projects
21.02.2017 | Schweizerischer Nationalfonds SNF

nachricht Coastal wetlands excel at storing carbon
01.02.2017 | University of Maryland

All articles from Interdisciplinary Research >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

Novel breast tomosynthesis technique reduces screening recall rate

21.02.2017 | Medical Engineering

Use your Voice – and Smart Homes will “LISTEN”

21.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>