Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Spintronics Advance Brings Wafer-Scale Quantum Devices Closer to Reality

29.06.2015

An electronics technology that uses the “spin” – or magnetization – of atomic nuclei to store and process information promises huge gains in performance over today’s electron-based devices. But getting there is proving challenging.

Now researchers at the University of Chicago’s Institute for Molecular Engineering (IME) have made a crucial step toward nuclear spintronic technologies. They have gotten nuclear spins to line themselves up in a consistent, controllable way, and they have done it using a high-performance material that is practical, convenient, and inexpensive.


Peter Allen

Light polarizes silicon nuclear spins within a silicon carbide chip. This image portrays the nuclear spin of one of the atoms shown in the full crystal lattice below.

“Our results could lead to new technologies like ultra-sensitive magnetic resonance imaging, nuclear gyroscopes, and even computers that harness quantum mechanical effects,” said Abram Falk, the lead author of the report on the research, which was featured as the cover article of the June 17 issue of Physical Review Letters. Falk and colleagues in David Awschalom’s IME research group invented a new technique that uses infrared light to align spins. And they did so using silicon carbide (SiC), an industrially important semiconductor.

Nuclear spins tend to be randomly oriented. Aligning them in a controllable fashion is usually a complicated and only marginally successful proposition. The reason, explains Paul Klimov, a co-author of the paper, is that “the magnetic moment of each nucleus is tiny, roughly 1,000 times smaller than that of an electron.”

This small magnetic moment means that little thermal kicks from surrounding atoms or electrons can easily randomize the direction of the nuclear spins. Extreme experimental conditions such as high magnetic fields and cryogenic temperatures
(-238 degrees Fahrenehit and below) are usually required to get even a small number of spins to line up. In magnetic resonance imaging (MRI), for example, only one to 10 out of a million nuclear spins can be aligned and seen in the image, even with a high magnetic field applied.

Using their new technique, Awschalom and his associates aligned more than 99 percent of spins in certain nuclei in silicon carbide (SiC). Equally important, the technique works at room temperature — no cryogenics or intense magnetic fields needed. Instead, the research team used light to “cool” the nuclei.

While nuclei do not themselves interact with light, certain imperfections, or “color-centers,” in the SiC crystals do. The electron spins in these color centers can be readily optically cooled and aligned, and this alignment can be transferred to nearby nuclei. Had the group tried to achieve the same degree of spin alignment without optical cooling they would have had to chill the SiC chip physically to just five millionths of a degree above absolute zero (-459.6 degrees Fahrenheit).

Getting spins to align in room-temperature silicon carbide brings practical spintronic devices a significant step closer, said Awschalom, the Liew Family Professor in Spintronics and Quantum Information. The material is already an important semiconductor in the high-power electronics and opto-electronics industries. Sophisticated growth and processing capabilities are already mature. So prototypes of nuclear spintronic devices that exploit the IME researchers’ technique may be developed in the near future. Said Awschalom: “Wafer-scale quantum technologies that harness nuclear spins as subatomic elements may appear more quickly than we anticipated.” —Carla Reiter

Citation: “Optical Polarization of Nuclear Spins in Silicon Carbine,” by Abram L. Falk, Paul V. Klimov, Viktor Ivády, Krisztián Szász, David J. Christle, William F. Koehl, Ádám Gali, and David D. Awschalom, Physical Review Letters, 114, 247603 (2015), DOI: 10.1103. Published June 17, 2015.

Funding and support: Air Force Office of Scientific Research, National Science Foundation, Knut & Alice Wallenberg Foundation, Hungarian Academy of Sciences, and Sweden’s National Supercomputer Center.

Contact Information
Steve Koppes
Associate News Director
skoppes@uchicago.edu
Phone: 773-702-8366

Steve Koppes | newswise
Further information:
http://www.uchicago.edu

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

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>