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 A Dream for the Future: “Flying with Green Fuel"
25.07.2018 | Universität Bremen

nachricht Investigating cell membranes: researchers develop a substance mimicking a vital membrane component
25.05.2018 | Westfälische Wilhelms-Universität Münster

All articles from Interdisciplinary Research >>>

The most recent press releases about innovation >>>

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

Im Focus: Hygiene at your fingertips with the new CleanHand Network

The Fraunhofer FEP has been involved in developing processes and equipment for cleaning, sterilization, and surface modification for decades. The CleanHand Network for development of systems and technologies to clean surfaces, materials, and objects was established in May 2018 to bundle the expertise of many partnering organizations. As a partner in the CleanHand Network, Fraunhofer FEP will present the Network and current research topics of the Institute in the field of hygiene and cleaning at the parts2clean trade fair, October 23-25, 2018 in Stuttgart, at the booth of the Fraunhofer Cleaning Technology Alliance (Hall 5, Booth C31).

Test reports and studies on the cleanliness of European motorway rest areas, hotel beds, and outdoor pools increasingly appear in the press, especially during...

Im Focus: Scientists present new observations to understand the phase transition in quantum chromodynamics

The building blocks of matter in our universe were formed in the first 10 microseconds of its existence, according to the currently accepted scientific picture. After the Big Bang about 13.7 billion years ago, matter consisted mainly of quarks and gluons, two types of elementary particles whose interactions are governed by quantum chromodynamics (QCD), the theory of strong interaction. In the early universe, these particles moved (nearly) freely in a quark-gluon plasma.

This is a joint press release of University Muenster and Heidelberg as well as the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt.

Then, in a phase transition, they combined and formed hadrons, among them the building blocks of atomic nuclei, protons and neutrons. In the current issue of...

Im Focus: Patented nanostructure for solar cells: Rough optics, smooth surface

Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.

"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...

Im Focus: New soft coral species discovered in Panama

A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.

Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...

Im Focus: New devices based on rust could reduce excess heat in computers

Physicists explore long-distance information transmission in antiferromagnetic iron oxide

Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

"Boston calling": TU Berlin and the Weizenbaum Institute organize a conference in USA

21.09.2018 | Event News

One of the world’s most prominent strategic forums for global health held in Berlin in October 2018

03.09.2018 | Event News

4th Intelligent Materials - European Symposium on Intelligent Materials

27.08.2018 | Event News

 
Latest News

Establishing metastasis

25.09.2018 | Health and Medicine

Artificial intelligence to improve drug combination design & personalized medicine

25.09.2018 | Health and Medicine

Small modulator for big data

25.09.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>