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.
Producing electricity during flight
20.09.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
Solar-to-fuel system recycles CO2 to make ethanol and ethylene
19.09.2017 | DOE/Lawrence Berkeley National Laboratory
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...
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21.09.2017 | Health and Medicine