A team of engineers and scientists has identified a source of electronic noise that could affect the functioning of instruments operating at very low temperatures, such as devices used in radio telescopes and advanced physics experiments. The findingscould have implications for the future design of transistors and other electronic components.
In classrooms and everyday conversation, explanations of global warming hinge on the greenhouse gas effect. In short, climate depends on the balance between two different kinds of radiation: The Earth absorbs incoming visible light from the sun, called “shortwave radiation,” and emits infrared light, or “longwave radiation,” into space.
Scientists from SLAC National Accelerator Laboratory and the Univ. of California, Los Angeles have shown that a promising technique for accelerating electrons on waves of plasma is efficient enough to power a new generation of shorter, more economical accelerators. This could greatly expand their use in areas such as medicine, national security, industry and high-energy physics research.
The process of phase changes- those transitions between states of matter- is more complex than previously thought. A team researchers has found that we may need to rethink one of science’s building blocks and illustrate how a proper theoretical description of transitions has remained unclear.
Last year CERN announced the finding of a new elementary particle, the Higgs particle. But, maybe it wasn't the Higgs particle– maybe it just looks like it. And maybe, it is not alone.
A reliable way of predicting the flow of traffic could be a great convenience for commuters, as well as a significant energy-saver. Now a team of researchers from MIT, the Univ. of Notre Dame, and elsewhere has devised what they say is an effective and relatively simple formula for making such predictions.
Scientists from the Department of Energy's SLAC National Accelerator Laboratory and the Univ. of California, Los Angeles have shown that a promising technique for accelerating electrons on waves of plasma is efficient enough to power a new generation of shorter, more economical accelerators.
The physics community has spent decades searching for and finding no evidence that dark matter is made of tiny exotic particles. Case Western Reserve Univ. theoretical physicists suggest researchers consider looking for candidates more in the ordinary realm and, well, more massive. Dark matter is unseen matter, that, combined with normal matter, could create the gravity that, among other things, prevents spinning galaxies from flying apart.
Results from experiments at the Relativistic Heavy Ion Collider, a particle collider located at the Brookhaven National Laboratory, reveal new insights about how quarks and gluons, the subatomic building blocks of protons, contribute to the proton’s intrinsic angular momentum, a property more commonly known as “spin.”
If you can uniformly break the symmetry of nanorod pairs in a colloidal solution, you’re a step ahead of the game toward achieving new and exciting metamaterial properties. But traditional thermodynamic-driven colloidal assembly of these metamaterials, which are materials defined by their non-naturally-occurring properties, often result in structures with high degree of symmetries in the bulk material.
Two Univ. of Southern California researchers have proposed a link between string field theory and quantum mechanics that could open the door to using string field theory as the basis of all physics. In their paper, which reformulated string field theory in a clearer language, they showed a set of fundamental quantum mechanical principles known as “commutation rules’’ that may be derived from the geometry of strings joining and splitting.
A disappearing act was the last thing Rice Univ. physicist Randy Hulet expected to see in his ultracold atomic experiments, but that is what he and his students produced by colliding pairs of Bose Einstein condensates (BECs) that were prepared in special states called solitons. Hulet’s team documented the strange phenomenon in a new study published online in Nature Physics.
Researchers studying iron-based superconductors are combining novel electronic structure algorithms with the high-performance computing power of the U.S. Dept. of Energy’s Titan supercomputer at Oak Ridge National Laboratory to predict spin dynamics, or the ways electrons orient and correlate their spins in a material.
In an international study Univ. of Melbourne and NIST found that pairs of closely spaced nanoparticles made of gold can act as “optical antennas”. These antennae concentrate the light shining on them into tiny regions located in the gap between the nanoparticles. Researchers found the precise geometry of nanoparticle pairs that maximizes light concentration, resolving a hotly debated area of quantum physics.
Researchers have succeeded in directing the fluorescence of ultracold atoms into surface plasmons, or light waves, oscillating across a metal surface. Physicists aim to create tiny systems in which things such as the interplay of light and matter may be observed at the level of individual photons. Such controlled systems hold the promise of applications such as transistors and switches depending on a single photon.
A significant breakthrough in laser technology has been reported by Lawrence Berkeley National Laboratory and the Univ. of California, Berkeley. The team of scientists have developed a unique microring laser cavity that can produce single-mode lasing even from a conventional multi-mode laser cavity.
A team led by the Lawrence Livermore National Laboratory scientists has created a new kind of ion channel consisting of short carbon nanotubes, which can be inserted into synthetic bilayers and live cell membranes to form tiny pores that transport water, protons, small ions and DNA. These carbon nanotube “porins” have significant implications for future health care and bioengineering applications.
Researchers in Japan have directly observed and recorded electron flow at 80,000 m/sec in a semiconductor. They did so by combining a new laser pulse light source and a photoemission electron microscope to develop an ultra high-speed microscope that enabled visualization of electrons on a 20 nm and 200 femtosec scale.
Electrons are elementary particles, indivisible, unbreakable. But new research at Brown Univ. suggests the electron's quantum state, known as the electron wave function, can be separated into many parts and trapped in tiny bubbles of liquid helium. That has some strange implications for the theory of quantum mechanics.
When researchers at General Electric Co. sought help in designing a plasma-based power switch, they turned to the Princeton Plasma Physics Laboratory, which helped them develop a plasma-filled tube that would replace semiconductor switches used for changing direct current to alternating current. The proposed switch could contribute to a more advanced and reliable electric grid and help to lower utility bills.
Quantum technology devices, such as high-precision sensors and specialised superfast computers, often depend on harnessing the delicate interaction of atoms. However, the methods for trapping these tiny particles are hugely problematic because of the atoms’ tendency to interact with their immediate environment. Scientists in the U.K. have recently shown how to make a new type of flexibly designed microscopic trap for atoms.
Scientists at Syracuse Univ. have made important discoveries regarding Bs meson particles, something that may explain why the universe contains more matter than antimatter. Prof. Sheldon Stone and his colleagues recently announced their findings at a workshop at CERN in Geneva, Switzerland.
A research team led by a Brown Univ. physicist has produced new evidence for an exotic superconducting state, first predicted a half-century ago, that can arise when a superconductor is exposed to a strong magnetic field. This new understanding of what happens when electron spin populations become unequal could have implications beyond superconductivity.
Lasers are so deeply integrated into modern technology that their basic operations would seem well understood. CD players, medical diagnostics and military surveillance all depend on lasers. Re-examining longstanding beliefs about the physics of these devices, Princeton Univ. engineers have now shown that carefully restricting the delivery of power to certain areas within a laser could boost its output by many orders of magnitude.
Helium is a famously unreactive gas but when cooled to just above absolute zero it becomes a superfluid, a strange form of liquid. An Anglo-Austrian team has used this liquid to develop a completely new way of forming charged particles. The team’s key discovery is that helium atoms can acquire an excess negative charge which enables them to become aggressive new chemical reagents.