Graphene, a two-dimensional crystalline form of carbon, is being touted as a sort of "Holy Grail" of materials. It boasts properties such as a breaking strength 200 times greater than steel and, of great interest to the semiconductor and data storage industries, electric currents that can blaze through it 100 times faster than in silicon.
Spintronic devices are being hotly pursued because they promise to be smaller, more versatile, and much faster than today's electronics. "Spin" is a quantum mechanical property that arises when a particle's intrinsic rotational momentum creates a tiny magnetic field. And spin has a direction, either "up" or "down." The direction can encode data in the 0s and 1s of the binary system, with the key here being that spin-based data storage doesn't disappear when the electric current stops.
"There is strong research interest in spintronic devices that process information using electron spins, because these novel devices offer better performance than traditional electronic devices and will likely replace them one day," says Kwok Sum Chan, professor of physics at the City University of Hong Kong "Graphene is an important material for spintronic devices because its electron spin can maintain its direction for a long time and, as a result, information stored isn't easily lost."
It is, however, difficult to generate a spin current in graphene, which would be a key part of carrying information in a graphene spintronic device. Chan and colleagues came up with a method to do just that. It involves using spin splitting in monolayer graphene generated by ferromagnetic proximity effect and adiabatic (a process that is slow compared to the speed of the electrons in the device) quantum pumping. They can control the degree of polarization of the spin current by varying the Fermi energy (the level in the distribution of electron energies in a solid at which a quantum state is equally likely to be occupied or empty), which they say is very important for meeting various application requirements.
The article, "Spin current generation by adiabatic pumping in monolayer graphene," by Qingtian Zhang, K. S. Chan, and Zijing Lin appears in the journal Applied Physics Letters. See: http://link.aip.org/link/applab/v98/i3/p032106/s1
Journalists may request a free PDF of this article by contacting firstname.lastname@example.org
NOTE: An image is available for journalists. Please contact email@example.com
CAPTION: This schematic of a graphene spin current pump shows a ferromagnetic layer deposited on a monolayer of graphene between two metal gates.
ABOUT APPLIED PHYSICS LETTERS
Applied Physics Letters, published by the American Institute of Physics, features concise, up-to-date reports on significant new findings in applied physics. Emphasizing rapid dissemination of key data and new physical insights, Applied Physics Letters offers prompt publication of new experimental and theoretical papers bearing on applications of physics phenomena to all branches of science, engineering, and modern technology. Content is published online daily, collected into weekly online and printed issues (52 issues per year). See: http://apl.aip.org/
The American Institute of Physics is a federation of 10 physical science societies representing more than 135,000 scientists, engineers, and educators and is one of the world's largest publishers of scientific information in the physical sciences. Offering partnership solutions for scientific societies and for similar organizations in science and engineering, AIP is a leader in the field of electronic publishing of scholarly journals. AIP publishes 12 journals (some of which are the most highly cited in their respective fields), two magazines, including its flagship publication Physics Today; and the AIP Conference Proceedings series. Its online publishing platform Scitation hosts nearly two million articles from more than 185 scholarly journals and other publications of 28 learned society publishers.
Jason Socrates Bardi | EurekAlert!
Meteoritic stardust unlocks timing of supernova dust formation
19.01.2018 | Carnegie Institution for Science
Artificial agent designs quantum experiments
19.01.2018 | Universität Innsbruck
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy