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.
Certain quantum physical phenomena in matter can only be clearly visualized in the presence of extreme magnetic fields. Physicists in Germany are developing a new high field magnet based on a hybrid design conceived in the U.S. On Oct. 16, 2014, scientists with the High Field Magnet project reported consistent magnetic fields of 26 T, higher than 25-T goal originally conceived.
An international team of scientists have become the first to successfully reach temperatures below -272.15 C, which is just above absolute zero, using magnetic molecules. The effort, which avoids the use of helium, depends on a form of gadolinium that appropriately has a structure resembling a snowflake.
Action-packed science-fiction movies often feature colorful laser bolts. But what would a real laser missile look like during flight, if we could only make it out? How would it illuminate its surroundings? The answers lie in a film made by researchers in Poland who have captured the passage of an ultrashort laser pulse through the air.
Scientists at Ames Laboratory have developed deeper understanding of the ideal design for mesoporous nanoparticles used in catalytic reactions, such as hydrocarbon conversion to biofuels. The research will help determine the optimal diameter of channels within the nanoparticles to maximize catalytic output.
Laser physicists in Australia have built a tractor beam that can repel and attract objects, using a hollow laser beam that is bright around the edges and dark in its center. It is the first long-distance optical tractor beam and has moved particles one-fifth of a millimeter in diameter a distance of up to 20 cm, around 100 times further than previous experiments.
Research by an international team of scientists has uncovered a new, unpredicted behavior in a copper oxide material that becomes superconducting at relatively high temperatures. This new phenomenon presents a challenge to scientists seeking to understand its origin and connection with high-temperature superconductivity. Their ultimate goal is to design a superconducting material that works at room temperature.
Joint Quantum Institute scientists have been developing a model for what happens when ultracold atomic spins are trapped in an optical lattice structure with a “double-valley” feature, where the repeating unit resembles the letter “W”. This new theory result opens up a novel path for generating what’s known as the spin Hall effect, an important example of spin-transport.
Like dancers swirling on the dance floor with bystanders looking on, protons and neutrons that have briefly paired up in the nucleus have higher-average momentum, leaving less for non-paired nucleons. Using data from nuclear physics experiments, researchers have now shown for the first time that this phenomenon exists in nuclei heavier than carbon, including aluminum, iron and lead.
Using extremely faint light from galaxies 10.8-billion light-years away, scientists have created one of the most complete, 3-D maps of a slice of the adolescent universe. The map shows a web of hydrogen gas that varies from low to high density at a time when the universe was made of a fraction of the dark matter we see today.
River beds, where flowing water meets silt, sand and gravel, are critical ecological zones. Yet how water flows in a river with a gravel bed is very different from the traditional model of a sandy river bed, according to a new study that compares their fluid dynamics. The findings establish new parameters for river modeling that better represent reality, with implications for field researchers and water resource managers.
Magnetic materials store the vast majority of the 2.7 zettabytes of data that are currently held worldwide. In the interest of efficiency, scientists have begun to investigate whether magnetic materials can also be used to perform calculations. In a recent paper, researchers in the U.K. detail their plan to harness swirling “tornadoes” of magnetization in nanowires to perform logic functions. They plan to soon build prototypes.
In a recent article published in the Review of Scientific Instruments, a research team led by scientists at Lawrence Livermore National Laboratory describe a technique for 3-D image processing of a high-speed photograph of a target, "freezing" its motion and revealing hidden secrets. This technique is particularly applicable in targets that are "shocked."
It’s not as bizarre as it sounds. Earth’s magnetic field has flipped many times throughout the planet’s history. Its dipole magnetic field, like that of a bar magnet, remains about the same intensity for thousands to millions of years, but for incompletely known reasons it occasionally weakens and, presumably over a few thousand years, reverses direction.