A bullet fired through a block of wood will slow down. In a similar way, ions are decelerated when they pass through a solid material: the thicker the material, the larger the energy loss will be. However, as recent experiments in Austria have shown, this picture breaks down in ultra-thin target materials, which only consist of a few layers of atoms.
Detected by NASA's orbiting Kepler telescope, a...
Scientists at Yale Univ. have confirmed a 50-year-old, previously untested theoretical...
Carefully timed pairs of laser pulses at the Linac...
A quasiparticle called an exciton has been understood theoretically for decades. But exciton movement within materials has never been directly observed. Now scientists have achieved that feat, imaging excitons’ motions directly. This could enable research leading to significant advances in electronics, they say, as well as a better understanding of natural energy-transfer processes, such as photosynthesis.
A fluctuating tilt in a planet’s orbit does not preclude the possibility of life, according to new research by a team of astronomers. In fact, sometimes it helps because such “tilt-a-worlds,” as astronomers sometimes call them, are less likely than fixed-spin planets to freeze over, as heat from their host star is more evenly distributed.
According to a new study, coupling commercially available spectral x-ray detectors with a specialized algorithm can improve the detection of uranium and plutonium in small, layered objects such as baggage. This approach enhances the detection powers of x-ray imaging and may provide a new tool to impede nuclear trafficking.
Following an upgrade of the Continuous Electron Beam Accelerator Facility at the Thomas Jefferson National Accelerator Facility, the accelerator delivered the highest-energy electron beams it has ever produced into a target, recording the first data of the 12 GeV era. The machine sent electrons around the racetrack three times, resulting in 6.11 GeV electrons at 2 nanoAmps average current for more than an hour.
Recent research using free-electron laser sources has enhanced the understanding of the interface of two materials, where completely new properties can arise. For instance, two insulators and non-magnetic materials can become metallic and magnetic at their interface. The breakthrough was the discovery of a discrepancy in the number of charge carriers of two promising electronic materials.
As yet, no one has found supersymmetry in our universe, including at the Large Hadron Collider. This absence of empirical evidence hasn’t stopped physicist Tarun Grover from being able to provide definitive mathematical evidence for supersymmetry in a condensed matter system. Sought after in the realm of subatomic particles by physicists for several decades, supersymmetry describes a unique relationship between particles.
Astronomers at Penn State and other institutions participating in the Sloan Digital Sky Survey have used 140,000 distant quasars to measure the expansion rate of the universe when it was only one-quarter of its present age. This measurement is the best yet of the expansion rate at any epoch in the last 13 billion years during the history of the universe.
Researchers from the NIST Center for Nanoscale Science and Technology have observed electromagnetically induced transparency at room temperature and atmospheric pressure in a silicon nitride optomechanical system. This work highlights the potential of silicon nitride as a material for producing integrated devices in which mechanical vibrations can be used to manipulate and modify optical signals.
An international team of scientists has reported the first experimental observation of the quantum critical point (QCP) in the extensively studied “unconventional superconductor” TiSe2, finding that it does not reside as predicted within the superconducting dome of the phase diagram, but rather at a full GPa higher in pressure.
Using a laser to place individual rubidium atoms near the surface of a lattice of light, scientists at Massachusetts Institute of Technology and Harvard Univ. have developed a new method for connecting particles—one that could help in the development of powerful quantum computing systems.
Traditionally, scientists discover new materials, and then probe them to understand their properties. Theoretical materials physicist Craig Fennie does it in reverse. He creates new materials by employing a "first principles" approach based on quantum mechanics, in which he builds materials atom by atom, starting with mathematical models, in order to gain the needed physical properties.
Recent experiments in Austria have explained the behavior of electrons at tiny step edges on titanium oxide surfaces. The finding, which shows why oxygen atoms attach so well to these edges, is important for solar cell technology and novel, more effective catalysts.
In steel making, two desirable qualities, strength and ductility, tend to be at odds: Stronger steel is less ductile, and more ductile steel is not as strong. Engineers at Brown Univ., three Chinese universities, and the Chinese Academy of Sciences have shown that when cylinders of steel are twisted, their strength is improved without sacrificing ductility.
The next time you feel a sneeze coming on, raise your elbow to cover up that multiphase turbulent buoyant cloud you’re about to expel. That’s right: A novel study by Massachusetts Institute of Technology researchers shows that coughs and sneezes have associated gas clouds that keep their potentially infectious droplets aloft over much greater distances than previously realized.
New research from North Carolina State Univ. and UNC-Chapel Hill reveals that energy is transferred more efficiently inside of complex, 3-D organic solar cells when the donor molecules align face-on, rather than edge-on, relative to the acceptor. This finding may aid in the design and manufacture of more efficient and economically viable organic solar cell technology.
New Yale Univ.-led research suggests how and when Earth came to develop one of its most distinct features—rigid tectonic plates—and why Venus, Earth’s twin-like neighbor, never has. Earth has a unique network of shifting plates embedded in its cold and rocky outermost layer, the lithosphere. The motion of these plates drives many Earth processes, while also stabilizing the planet’s climate and enabling life.
A combined computational and experimental study of self-assembled silver-based structures known as superlattices has revealed an unusual and unexpected behavior: arrays of gear-like molecular-scale machines that rotate in unison when pressure is applied to them.
As the properties and applications of graphene continue to be explored in laboratories all over the world, a growing number of researchers are looking beyond the one-atom-thick layer of carbon for alternative materials that exhibit similarly captivating properties.
Results from a recent applied science study at Caltech support the idea that waveguides coupled with another quantum particle—the surface plasmon—could also become an important piece of the quantum computing puzzle.
A new study of gamma-ray light from the center of our galaxy makes the strongest case to date that some of this emission may arise from dark matter, an unknown substance making up most of the material universe.
Astronomers are challenging the view that the currently preferred cosmological model of the Universe is correct. They are comparing recent measurements of the cosmic background radiation and galaxy clusters in two independent studies.
A new approach to studying solar panel absorber materials has been developed by researchers in France. The technique could accelerate the development of non-toxic and readily available alternatives to current absorbers in thin film-based solar cells.
A team of researchers has announced analytical prediction and numerical verification of novel quantum rotor states in nanostructured superconductors. The international collaborative team points out that the classical rotor, a macroscopic particle of mass confined to a ring, is one of the most studied systems in classical mechanics.
Using an acoustic metadevice that can influence the acoustic space and can control any of the ways in which waves travel, engineers have demonstrated, for the first time, that it is possible to dynamically alter the geometry of a 3-D colloidal crystal in real time. The crystals designed in the study, called metamaterials, are artificially structured materials that extend the properties of naturally occurring materials and compounds.
The fundamental laws of thermodynamics do not apply to objects on the nanoscale to the extent they do in our macroscopic world, and researchers are working to accurately describe the differences. A team of scientists have recently made progress in this area by determining how heat transfers from cold to hot objects in the nanoworld.
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