Superconductor “recipes” are frequently tweaked by swapping out elements or manipulating the valence electrons to strike the perfect conductive balance. Most high-temperature superconductors feature only one orbital impacting performance. But what about introducing more complex configurations? Now, Brookhaven National Laboratory’s physicists have combined atoms with multiple orbitals and precisely pinned down their electron distributions.
For centuries, geologists have recognized that the rocks that line riverbeds tend to be smaller and rounder further downstream. But these experts have not agreed on the reason these patterns exist. Does abrasion reduce the size of rocks significantly, or is it that smaller rocks are simply more easily transported downstream? A new study has arrived at a resolution to this puzzle.
An undesired effect in thin film amorphous silicon solar cells has puzzled the scientific community for the last 40 years. This effect, known as light-induced degradation, is responsible for reducing solar cell efficiency over time. Researchers in Germany have recently demonstrated that tiny voids within the silicon network are partly responsible for 10 to 15% efficiency loss as soon as they are used.
A team in France has greatly miniaturized the light-emitting diode (LED) by creating one from a single polythiophene wire placed between the tip of a scanning tunneling microscope and a gold surface. This nanowire, which is made of the same hydrogen, carbon and sulfur components found in much larger LEDs, emits light only when the current passes in a certain direction.
Modern electronics relies on utilizing the charge properties of the electron. The emerging field of atomtronics, however, uses ensembles of atoms to build analogs to electronic circuit elements. Physicists have built a superfluid atomtronic circuit that have allowed them to demonstrate a tool that is critical to electronics: hysteresis. It is the first time that hysteresis has been observed in an ultracold atomic gas.
Ignition has long been considered the "holy grail" of inertial confinement fusion science. A key step along the path to ignition is to have "fuel gains" greater than unity, where the energy generated through fusion reactions exceeds the amount of energy deposited into the fusion fuel. Though ignition remains the ultimate goal, the milestone of achieving fuel gains greater than one has been reached for the first time ever on any facility.
It's not quite Star Trek communications—yet. But long-distance communications in space may be easier now that researchers have designed a clever detector array that can extract more information than usual from single particles of light. Described in a new paper, the NIST/JPL array-on-a-chip easily identifies the position of the exact detector in a multi-detector system that absorbs an incoming infrared light particle, or photon.
New research at the Univ. of Arkansas reveals a novel magnetoelectric effect that makes it possible to control magnetism with an electric field. The novel mechanism may provide a new route for using multiferroic materials for the application of RAM (random access memories) in computers and other devices, such as printers.
Strange events have long been linked to nights of a full moon, though careful scrutiny dispels any association. So, when signals bounced off the lunar surface returned surprisingly faint echoes on full moon nights, scientists sought an explanation in reason rather than superstition. Still, the most compelling evidence arrived during another event that once evoked irrational fears, on a night when Earth's shadow eclipsed the full moon.
Molecular physicists in The Netherlands have produced images of the changes in direction of colliding nitrogen monoxide molecules (NO) with unprecedented sharpness. By combining a Stark decelerator with advanced imaging techniques, they were able to obtain very high resolution images of the collision processes. The finding sheds light on the wave nature of molecules by imaging what previously had only been theorized.
Engineers are increasingly turning to plasmonic color filters (PCFs) to create and control a broad spectrum of colors for imaging applications. However, PCF light transmission efficiency has been limited to only about 30%, less than half the rate of conventional filters. Researchers have now developed a new PCF scheme that achieves a transmission efficiency of 60 to 70%.
U.S. Army-sponsored researchers have discovered a process for simultaneously storing and dissipating energy within structures that could lead to design rules for new types of active, reconfigurable materials. The study method was derived from an examination of how a species of South American fire ant collectively entangle themselves to form an active structure capable of changing state from a liquid to a solid when subject to applied loads.
Seeking a solution to decoherence, scientists have developed a strategy of linking quantum bits together into voting blocks, a strategy that significantly boosts their accuracy. In a recently published paper, the team found that their method results in at least a five-fold increase in the probability of reaching the correct answer when the processor solves the largest problems tested by the researcher, involving hundreds of qubits.
Topological insulators have been of great interest to physicists in recent years because of unusual properties that may provide insights into quantum physics. But most analysis of such materials has had to rely on highly simplified models. Now, a team of researchers at Massachusetts Institute of Technology has performed a more detailed analysis that hints at the existence of six new kinds of topological insulators.
Lead-free BaTiO3 and KNbO3 ferroelectrics have been known and studied for more than 60 years. However, recent scanning x-ray diffraction studies at Argonne National Laboratory have shown new low-symmetry intermediate phases in these materials that lend a thermotropic character to otherwise well-known phase transitions. The findings show that these transitions in ferroelectrics are closely coupled to the underlying domain microstructure.
Cars inch forward slowly in traffic jams, but molecules, when jammed up, can move extremely fast. New research by Northwestern Univ. researchers finds that water molecules traveling through tiny carbon nanotube pipes do not flow continuously but rather intermittently, like stop-and-go traffic, with unexpected results.
An international team of researchers from France and the United States have devised an entirely new way to synthesize graphene ribbons with defined, regular edges, allowing electrons to flow freely through the material. Demonstrating this phenomenon at room temperature, the material was shown to permit electron flow up to 200 times faster than through silicon.
Texas Advanced Computing Center recently reported the results of several massive numerical simulations charting the forces of the universe in its first hundreds of millions of years. The study, which used some of the world's most powerful supercomputers, has refined our understanding of how the first galaxies formed, and, in particular, how metals in the stellar nurseries influenced the characteristics of the stars in the first galaxies.
We all learn in high school science about the dual nature of light—that it exists as both waves and quantum particles called photons. It’s this duality of light that enables the coherent transport of photons in lasers. Sound at the atomic-scale has the same dual nature, existing as both waves and quasi-particles known as phonons. Does this duality allow for phonon-based lasers?
Using electrons more like photons could provide the foundation for a new type of electronic device that would capitalize on the ability of graphene to carry electrons with almost no resistance even at room temperature—a property known as ballistic transport. Research reported that electrical resistance in nanoribbons of epitaxial graphene changes in discrete steps following quantum mechanical principles.
A team NIST scientists, with collaborators elsewhere, has achieved a five-fold reduction in the dominant uncertainty in an experiment that measured the mean lifetime of the free neutron, resulting in a substantial improvement of previous results. However, the accomplishment reveals a puzzling discrepancy when compared to different method, and researchers are planning to re-run the experiment in upgraded form.
New research shows that a remarkable defect in synthetic diamond produced by chemical vapor deposition allows researchers to measure, witness, and potentially manipulate electrons in a manner that could lead to new “quantum technology” for information processing.
Scientists have used a particle physics theory to describe the behavior of particle-like entities, referred to as excitons, in two layers of graphene. The use of equations typically employed in high-energy physics has prompted the authors to suggest a design for an experimental device relying on a magnetically tunable optical filter that could verify their predictions.
Researchers in the George E. Brown, Jr. Network for Earthquake Engineering Simulation have studied concrete buildings constructed before roughly 1980 in the Los Angeles area. Their work has identified examples of this category of buildings, sometimes referred to as nonductile concrete buildings, which are known from experience in previous earthquakes to have the potential for catastrophic collapse during strong earthquakes.
The same physics that gives tornadoes their ferocious stability lies at the heart of new Univ. of Washington research, and could lead to a better understanding of nuclear dynamics in studying fission, superconductors and the workings of neutron stars. The work seeks to clarify what Massachusetts Institute of Technology researchers witnessed when in 2013 they named a mysterious phenomenon.