In two complementary studies, an international team of physicists has now established that superconductivity in high-temperature superconductors, known as cuprates, collapses at a maximum of -135 C due to the formation of charge-density waves. Consequently, in order to find superconductors that drop to zero resistance at realistic temperatures, materials scientists must search for substances that are not subject to charge-density waves.
Nearly 25% of earthquakes occur more than 50 km below the Earth’s surface in a region called the lithosphere. But limited data and knowledge have prevented researchers from finding the cause of these intermediate and deep earthquakes. A team has recently found immense heating at high pressures at these depths, helping explain the “runaway” process propagates an earthquake in the lithosphere.
It's hard to study individual molecules in a gas because they tumble around chaotically and never sit still. Researchers in California overcame this challenge by using a laser to point them in the same general direction, like compass needles responding to a magnet, so they could be more easily studied with an x-ray laser. It’s a key step toward producing movies that show how a single molecule changes during a chemical reaction.
Researchers in Switzerland studying a natural wetland near a decommissioned uranium mine in Limousin, France, have shown that under certain circumstances the uranium present in the wetland could be more mobile than previously believed.
Astronomers affiliated with the Supernova Legacy Survey (SNLS) have discovered two of the brightest and most distant supernovae ever recorded, 10 billion light-years away and a hundred times more luminous than a normal supernova. These newly discovered supernovae are especially puzzling because the mechanism that powers most of them cannot explain their extreme luminosity.
Researchers at The Univ. of Texas at Austin have proposed the first design of a cloaking device that uses an external source of energy to significantly broaden its bandwidth of operation. The team has proposed a design for an active cloak that draws energy from a battery, allowing objects to become undetectable to radio sensors over a greater range of frequencies.
The sound vibrations that make up music can make solar panels work harder, according to new research, and pop music performs better than classical. Scientists showed that high pitched sounds like those common in pop and rock music caused the greatest improvement in the solar cells' power output, increasing it by up to 40%.
A Lawrence Livermore National Laboratory team has recently produced some of the highest energy betatron x-rays ever demonstrated, with the added benefit of being produced on a system the size of a large tabletop. Betatron x-ray radiation, produced when relativistic electrons are accelerated and oscillate in a laser-driven plasma channel, is an x-ray source holding great promise for future high-energy-density science experiments.
In a sort of biological "spooky action at a distance," water in a cell slows down in the tightest confines between proteins and develops the ability to affect other proteins much farther away, Univ. of Michigan researchers have discovered. The finding could provide insights into how and why proteins clump together in diseases such as Alzheimer's and Parkinson's.
Stanene is the name given by researchers to 2-D sheets of tin that are only one atom thick. A Stanford Univ. team predicts stanene would be the first topological insulator to demonstrate zero heat dissipation properties at room temperature, conducting charges around its edges without any loss. Experiments are underway to create the material in the laboratory. If successful, stanene will enhance devices being built under a DARPA program.
Researchers based at Oak Ridge National Laboratory and the Univ. of Tennessee have discovered a molecular “switch” in a receptor that controls cell behavior. Researchers identified the molecular switch using detailed molecular dynamics simulations on a computer called Anton, built by D. E. Shaw Research in New York City.
Photolithography uses light beams to design thin geometric patterns on the substrates of semiconductors used in microelectronic devices, but the phenomenon of light diffraction does not permit highly accurate patterns. A new quantum lithography protocol from a scientist in Russia now makes it possible to improve the accuracy of photolithography by addressing its physical limitations.
Researchers in Spain, working with the firm Luz WaveLabs, are developing an innovative terahertz generator that improves signal quality by one million times as compared to the best device of this kind currently on the market. They have achieved this level of quality through the use, in part, of a specialized optical frequency comb and modifications to the laser source.
Scientists from the Hamburg Center for Free-Electron Laser Science have devised a novel way to boil water in less than a trillionth of a second. The theoretical concept, which uses terahertz radiation but has not yet been demonstrated in practice, could heat a small amount of water by as much as 600 C in just half a picosecond.
An international research team, including researchers at the Univ. of Basel in Switzerland was able to observe a strong energy loss caused by friction effects in the vicinity of charge density waves. This could have practical significance for the control of friction at the nanometer level.
Physicists in Germany have developed a “planet-satellite model” to precisely connect and arrange nanoparticles in 3-D structures. Inspired by the photosystems of plants and algae, these artificial nanoassemblies of DNA strands might in the future serve to collect and convert energy.
Scientists working to advance imaging useful to medicine and security are capitalizing on the same phenomenon behind the lingering "ghost" image that appeared on old television screens. A team of researchers has created a way to control the length of time light from a luminescent nanocrystal lingers, adding a new dimension of time to color and brightness in optical detection technology.
Researchers have tuned coherence in organic nanostructures due to the surprise discovery of wave-like electrons in organic materials, revealing the key to generating long-lived charges in organic solar cells. By using an ultra-fast camera, scientists have observed the very first instants following the absorption of light into artificial, organic nanostructures and found that charges formed rapidly and separated quickly over long distances.
Noble gas molecules have been detected in space for the first time in the Crab Nebula, a supernova remnant, by astronomers at Univ. College London. Led by Prof. Mike Barlow, the team used ESA's Herschel Space Observatory to observe the Crab Nebula in far infrared light. Their measurements of regions of cold gas and dust led them to the serendipitous discovery of the chemical fingerprint of argon hydride ions.
Strategies to manipulate light and sound go back to the first spherical glass bead and the pounding of the first hollow log. But their full potential is only just becoming apparent, according to a review by materials scientists at Rice Univ. and their colleagues. New abilities to corral light and sound from the macroscale to the nanoscale with structured polymers could deliver profound changes in the way we live.
Lawrence Livermore National Laboratory researchers have combined ultra-fast time-resolved experimental measurements with theory to reveal how an explosive responds to a high-impact shock. The work involved advances in both ultra-fast experimental shock wave methods and molecular dynamics (MD) simulation techniques, and the combination of experiment and simulation is a milestone in understanding chemical initiation and detonation.
Researchers have found a new way to probe molecules and atoms with an x-ray laser, setting off cascading bursts of light that reveal precise details of what is going on inside. The technique may allow scientists to see details of chemical reactions and home in on the properties of specific elements within complex molecules in a way not possible before.
Jupiter’s moon Europa features an intricate network of cracks in its icy surface. This unusual pattern is particularly pronounced around the equator. Scientists performing modeling studies on the potential marine currents below this ice layer have discovered that, near Europa’s equator, warmer water rises from deep within the moon.
Stanford Univ. scientists may have solved the mystery of what drives a type of earthquake that occurs deep within the Earth and accounts for one in four quakes worldwide. Known as intermediate-depth earthquakes, these temblors originate farther down inside the Earth than shallow earthquakes, which take place in the uppermost layer of the Earth's surface, called the crust.
By applying pressure to a semiconductor, researchers have been able to transform a semiconductor into a “topological insulator” (TI), an intriguing state of matter in which a material’s interior is insulating but its surfaces or edges are conducting with unique electrical properties. This is the first time that researchers have used pressure to gradually “tune” a material into the TI state.