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 A tale of two pulsars' tails: Plumes offer geometry lessons to astronomers
18.01.2017 | Penn State

nachricht Studying fundamental particles in materials
17.01.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie

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: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

A big nano boost for solar cells

18.01.2017 | Power and Electrical Engineering

Glass's off-kilter harmonies

18.01.2017 | Materials Sciences

Toward a 'smart' patch that automatically delivers insulin when needed

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>