Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A new spin on spintronics

18.02.2015

Michigan team tests radiation-resistant spintronic material, possibly enabling electronic devices that will work in harsh environments

A team of researchers from the University of Michigan and Western Michigan University is exploring new materials that could yield higher computational speeds and lower power consumption, even in harsh environments.


A laser pulse is split into two paths: circularly polarized pump (blue) and linearly polarized probe (red). The pump's path length is adjustable using a delay stage so that the relative arrival time between the pump and probe can be adjusted. After the probe is reflected from the sample surface, the light is passed through a Walloston Prism and sent to a balanced photo-diode bridge. This allows for very sensitive measurements of the Faraday rotation due to electron spin polarizations.

Credit: AIP Publishing

Most modern electronic circuitry relies on controlling electronic charge within a circuit, but this control can easily be disrupted in the presence of radiation, interrupting information processing. Electronics that use spin-based logic, or spintronics, may offer an alternative that is robust even in radiation-filled environments.

Making a radiation-resistant spintronic device requires a material relevant for spintronic applications that can maintain its spin-dependence after it has been irradiated. In a paper published in the journal Applied Physics Letters, from AIP Publishing, the Michigan research team presents their results using bulk Si-doped n-GaAs exposed to proton radiation.

How Does Spintronics Work?

Modern electronic devices use charges to transmit and store information, primarily based upon how many electrons are in one place or another. When a lot of them are at a given terminal, you can call that 'on.' If you have very few of them at the same terminal, you can call that 'off,' just like a light switch. This allows for binary logic depending on whether the terminal is 'on' or 'off.' Spintronics, at its simplest, uses the 'on/off' idea, but instead of counting the electrons, their spin is measured.

"You can think of the spin of an electron as a tiny bar magnet with an arrow painted on it. If the arrow points up, we call that 'spin-up.' If it points down, we call that 'spin-down.' By using light, electric, or magnetic fields, we can manipulate, and measure, the spin direction," said researcher Brennan Pursley, who is the first author of the new study.

While spintronics holds promise for faster and more efficient computation, researchers also want to know whether it would be useful in harsh environments. Currently, radioactivity is a major problem for electronic circuitry because it can scramble information and in the long term degrade electronic properties. For the short term effects, spintronics should be superior: radioactivity can change the quantity of charge in a circuit, but should not affect spin-polarized carriers.

Studying spintronic materials required that the research team combine two well established fields: the study of spin dynamics and the study of radiation damage. Both tool sets are quite robust and have been around for decades but combining the two required sifting through the wealth of radiation damage research. "That was the most difficult aspect," explains Pursley. "It was an entirely new field for us with a variety of established techniques and terminology to learn. The key was to tackle it like any new project: ask a lot of questions, find a few good books or papers, and follow the citations."

Technically, what the Michigan team did was to measure the spin properties of n-GaAs as a function of radiation fluence using time-resolved Kerr rotation and photoluminescence spectroscopy. Results show that the spin lifetime and g-factor of bulk n-GaAs is largely unaffected by proton irradiation making it a candidate for further study for radiation-resistant spintronic devices. The team plans to study other spintronic materials and prototype devices after irradiation since the hybrid field of irradiated spintronics is wide open with plenty of questions to tackle.

Long term, knowledge of radiation effects on spintronic devices will aid in their engineering. A practical implementation would be processing on a communications satellite where without the protection of Earth's atmosphere, electronics can be damaged by harsh solar radiation. The theoretically achievable computation speeds and low power consumption could be combined with compact designs and relatively light shielding. This could make communications systems faster, longer-lived and cheaper to implement.

 ###

The article, "Robustness of n-GaAs carrier spin properties to 5MeV proton radiation," is authored by Brennan Pursley, X. Song, R.O. Torres-Isea, E.A. Bokari, A. Kayani and V. Sih. It appears in the journal Applied Physics Letters on February 17, 2015 (DOI: 10.1063/1.4907286). After that date, it will be available at: http://scitation.aip.org/content/aip/journal/apl/106/7/10.1063/1.4907286

The authors of this paper are affiliated with the University of Michigan and Western Michigan University.

ABOUT THE JOURNAL

Applied Physics Letters features concise, rapid reports on significant new findings in applied physics. The journal covers new experimental and theoretical research on applications of physics phenomena related to all branches of science, engineering, and modern technology. See: http://apl.aip.org

Media Contact

Jason Socrates Bardi
jbardi@aip.org
240-535-4954

 @AIP_Publishing

http://www.aip.org 

Jason Socrates Bardi | EurekAlert!

More articles from Physics and Astronomy:

nachricht Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst

nachricht Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Northern oceans pumped CO2 into the atmosphere

27.03.2017 | Earth Sciences

Fingerprint' technique spots frog populations at risk from pollution

27.03.2017 | Life Sciences

Big data approach to predict protein structure

27.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>