By bombarding very thin slices of several copper/oxygen compounds, called cuprates, with very bright, short-lived pulses of light, Ivan Bozovic, a physicist at the U.S. Department of Energys Brookhaven National Laboratory, and his collaborators have discovered an unusual property of the materials: After absorbing the light energy, they emit it as long-lived sound waves, as opposed to heat energy. This result may open up a new field of study on cuprates -- materials already used in wireless communications and under investigation for other applications in the electronics industry.
As the light pulses strike each film, illuminating an area only about a thousandth of a millimeter across, they transfer their energy to the films atoms. In response, the atoms vibrate, and tiny sound wave "packets," called phonons, spread through the sample. Bozovic observes that, mysteriously, these emitted sound waves do not die out quickly, as they do with other materials. Instead, the atoms oscillate many times before dissipating the absorbed energy. "This is very unusual, as it seems that the atoms find it hard to convert these oscillations into ordinary thermal energy (heat)," said Bozovic.
Through further studies, Bozovic hopes to learn more about this phenomenon, the first step toward finding possible applications for it. For example, this work could contribute to the development of a phaser, a laser-like device that emits phonons instead of light. "Much more research needs to be done," Bozovic said. "We dont know yet how this property might be useful. However, I have little doubt that the phaser would be a very useful scientific tool for a broad new class of experiments," Bozovic said.
Silicon solar cell of ISFH yields 25% efficiency with passivating POLO contacts
08.12.2016 | Institut für Solarenergieforschung GmbH
Robot on demand: Mobile machining of aircraft components with high precision
06.12.2016 | Fraunhofer IFAM
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