Research professor Sergey Prosandeev and professor Laurent Bellaiche of the University of Arkansas and A.R. Akbarzadeh of the University of California-Los Angeles report the state, called incipient ferrotoroidics, in Physical Review Letters.
The researchers asked what happens to nanoscale materials at low temperatures. Classical mechanics predict that atoms stop moving at low temperatures, but quantum mechanics predict that atoms continue to vibrate even at low temperatures. Such quantum mechanical vibrations are known to cause the disappearance of the spontaneous electric polarization in some bulk materials, and these materials are called incipient ferroelectrics. However, scientists don’t know what happens to nanoscale materials at low temperatures.“What about the nanoscale ferroelectrics? Do they show quantum effects? Do they suppress polarization or promote new properties?” Prosandeev asked.
To answer these questions, the researchers modified the complicated computer codes aimed at resolving the behavior of bulk incipient ferroelectrics at low temperatures so they would describe nanostructures. They used the high-performance computing facility Star of Arkansas to perform the calculations. They performed both classical and quantum mechanics calculations, some of which took weeks using 128 processors.
At low temperatures, they discovered a new kind of quantum state of material. Called incipient ferrotoroidics, it is a state where quantum vibrations wash out the formation of recently discovered vortex states. This creates a situation where the material’s susceptibility to toroidal moment is high and independent of temperature – meaning that a small, curled field can create a strong vortex at any given moment.
“In electric capacitors we have electrons,” Prosandeev said. “Here we have topological charges instead.”
This means that it should be possible to create a new kind of device — namely, a topological charge capacitor — in nanoscale material at low temperatures. A vortex could be triggered in such a material using small changes in some chiral electric field.
“We predict that there is a way to prepare this original state of material,” Prosandeev said. “This opens the door to a new direction for applications and for thinking.”
This research was supported by grants from the Office of Naval Research and the National Science Foundation.CONTACTS:
Melissa Lutz Blouin | Newswise Science News
Decoding cement's shape promises greener concrete
08.12.2016 | Rice University
Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D
08.12.2016 | DOE/Brookhaven National Laboratory
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine