Researchers have made an important advance in the emerging field of 'spintronics' that may one day usher in a new generation of smaller, smarter, faster computers, sensors and other devices, according to findings reported in today's issue of the journal Nature Nanotechnology.
The research field of 'spintronics' is concerned with using the 'spin' of an electron for storing, processing and communicating information.
The research team of electrical and computer engineers from the Virginia Commonwealth University's School of Engineering and the University of Cincinnati examined the 'spin' of electrons in organic nanowires, which are ultra-small structures made from organic materials. These structures have a diameter of 50 nanometers, which is 2,000 times smaller than the width of a human hair. The spin of an electron is a property that makes the electron act like a tiny magnet. This property can be used to encode information in electronic circuits, computers, and virtually every other electronic gadget.
"In order to store and process information, the spin of an electron must be relatively robust. The most important property that determines the robustness of spin is the so-called 'spin relaxation time,' which is the time it takes for the spin to 'relax.' When spin relaxes, the information encoded in it is lost. Therefore, we want the spin relaxation time to be as long as possible," said corresponding author Supriyo Bandyopadhyay, Ph.D., a professor in the Department of Electrical and Computer Engineering at the VCU School of Engineering.
"Typically, the spin relaxation time in most materials is a few nanoseconds to a few microseconds. We are the first to study spin relaxation time in organic nanostructures and found that it can be as long as a second. This is at least 1000 times longer than what has been reported in any other system," Bandyopadhyay said.
The team fabricated their nanostructures from organic molecules that typically contain carbon and hydrogen atoms. In these materials, spin tends to remain relatively isolated from perturbations that cause it to relax. That makes the spin relaxation time very long.
The VCU-Cincinnati team was also able to pin down the primary spin relaxation mechanism in organic materials, which was not previously known. Specifically, they found that the principal spin relaxation mechanism is one where the spin relaxes when the electron collides with another electron, or any other obstacle it encounters when moving through the organic material. This knowledge can allow researchers to find means to make the spin relaxation time even longer.
"The organic spin valves we developed are based on self-assembled structures grown on flexible substrates which could have a tremendous impact on the rapidly developing field of plastic electronics, such as flexible panel displays," said Marc Cahay, Ph.D., a professor in the Department of Electrical and Computer Engineering at the University of Cincinnati. "If the organic compounds can be replaced by biomaterials, this would also open news areas of research for biomedical and bioengineering applications, such as ultra-sensitive sensors for early detection of various diseases."
"These are very exciting times to form interdisciplinary research teams and bring back the excitement about science and engineering in students at a very young age to raise them to become the future generations of nanopioneers," Cahay said.
The fact that the spin relaxation time in organic materials is exceptionally long makes them the ideal host materials for spintronic devices. Organic materials are also inexpensive, and therefore very desirable for making electronic devices.
The VCU-Cincinnati research advances nanotechnology, which is a rapidly growing field where engineers are developing techniques to create technical tools small enough to work at the atomic level. Additionally, by using nanoscale components researchers have the ability to pack a large number of devices within a very small area. The devices themselves are just billionths of a meter; and trillions of them can be packed into an area the size of a postage stamp. Furthermore, they consume very little energy when they process data.
In 1994, Bandyopadhyay and colleagues were the first group to propose the use of spin in classical computing. Then two years later, they were among the first researchers to propose the use of spin in quantum computing. The recent work goes a long way toward implementing some of these ideas.
The work is supported by the U.S. Air Force Office of Scientific Research and the National Science Foundation.
Sandipan Pamanik, a graduate student in the VCU School of Engineering's Department of Electrical and Computer Engineering, was first author of the study. The research team also included Carmen Stefanita, Ph.D., and graduate student, Sridhar Patibandla, both in the VCU Department of Electrical and Computer Engineering; and graduate students Kalyan Garre and Nick Harth from the University of Cincinnati's Department of Electrical and Computer Engineering.
Sathya Achia-Abraham | EurekAlert!
Cutting edge research for the industries of tomorrow – DFKI and NICT expand cooperation
21.03.2017 | Deutsches Forschungszentrum für Künstliche Intelligenz GmbH, DFKI
Molecular motor-powered biocomputers
20.03.2017 | Technische Universität Dresden
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...
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...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
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...
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...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy