A year before Albert Einstein came up with the special theory of relativity, or E=mc2, physicists predicted the existence of something else: cyclotron radiation. Scientists predicted this radiation to be given off by electrons whirling around in a circle while trapped in a magnetic field. Over the last century, scientists have observed this radiation from large ensembles of electrons but never from individual ones. Until now.
Most people are naturally adept at reading facial expressions — from smiling and frowning to brow-furrowing and eye-rolling — to tell what others are feeling. Now scientists have developed ultra-sensitive, wearable sensors that can do the same thing.
Quantum particles behave in strange ways and are often difficult to study experimentally. Using mathematical methods drawn from game theory, LMU physicists have shown how bosons, which like to enter the same state, can form multiple groups.
Physicists have shown how heat can be used to control the magnetic properties of matter. The finding helps in the development of more efficient mass memories. In the study, the researchers showed how heat is converted into a spin current in magnetic superconductors. Magnetic superconductors can be fabricated by placing a superconducting film on top of a magnetic insulator.
When a mirror reflects light, it experiences a slight push. This radiation pressure can be increased considerably with the help of a small superconducting island. The finding paves a way for the studies of mechanical oscillations at the level of a single photon, the quantum of light.
Add water to a half-filled cup and the water level rises. This everyday experience reflects a positive material property of the water-cup system. But what if adding more water lowers the water level by deforming the cup? This would mean a negative compressibility. Now, a quantum version of this phenomenon, called negative electronic compressibility (NEC), has been discovered.
Researchers have shown that a laser-generated microplasma in air can be used as a source of broadband terahertz radiation. They demonstrate that an approach for generating terahertz waves using intense laser pulses in air—first pioneered in 1993—can be done with much lower power lasers, a major challenge until now.
Building on their creation of the first-ever mechanical device that can measure the mass of individual molecules, one at a time, a team of scientists have created nanodevices that can also reveal their shape. Such information is crucial when trying to identify large protein molecules or complex assemblies of protein molecules.
They may deal in gold, atomic staples and electron volts rather than cement, support beams and kilowatt-hours, but chemists have drafted new nanoscale blueprints for low-energy structures capable of housing pharmaceuticals and oxygen atoms. New research has revealed four atomic arrangements of a gold nanoparticle cluster.
In another advance at the far frontiers of timekeeping by NIST researchers, the latest modification of a record-setting strontium atomic clock has achieved precision and stability levels that now mean the clock would neither gain nor lose one second in some 15 billion years—roughly the age of the universe.
Scientists have developed a new approach that combines ptychographic x-ray imaging and fluorescence microscopy to study the important role trace elements play in biological functions on hydrated cells. A team of researchers using the Advanced Photon Source demonstrated unparalleled sensitivity for measuring distribution of trace elements in thicker specimens at cryogenic temperatures, in this case at about 260 degrees below Fahrenheit.
A Spanish-led team of European researchers at the Univ. of Cambridge has created an electronic device so accurate that it can detect the charge of a single electron in less than one microsecond. It has been dubbed the "gate sensor" and could be applied in quantum computers of the future to read information stored in the charge or spin of a single electron.
Physicists have shown how heat can be exploited for controlling magnetic properties of matter. The finding helps in the development of more efficient mass memories. The result was published in Physical Review Letters. The international research group behind the breakthrough included Finnish researchers from the University of Jyväskylä and Aalto Univ.
Thermal imaging, microscopy and ultra-trace sensing could take a quantum leap with a technique developed by researchers at Oak Ridge National Laboratory. Their work overcomes fundamental limitations of detection derived from the Heisenberg uncertainty principle, which states that the position and momentum of a particle cannot be measured with absolute precision.
As the world’s exponentially growing demand for digital data slows the Internet and cell phone communication, City College of New York researchers may have just figured out a new way to increase its speed.
The silver used by Beth Gwinn’s research group at the Univ. of California, Santa Barbara, has value far beyond its worth as a commodity, even though it’s used in very small amounts. The group works with the precious metal to create nanoscale silver clusters with unique fluorescent properties. These properties are important for a variety of sensing applications including biomedical imaging.
Scientists are developing a portable technology that will safely and quickly detect nuclear material hidden within large objects such as shipping cargo containers or sealed waste drums. The researchers have been awarded over $10 million from the NNSA to combine the capabilities of conventional building-size research instruments with the transportable size of a truck for security applications on the go.
In the quantum world of light, being distinguishable means staying lonely. Only those photons that are indistinguishable can wind up in a pair, through what is called Hong-Ou-Mandel interference. This subtle quantum effect has been successfully imaged for the first time by two doctoral students from the Faculty of Physics at the University of Warsaw.
Albert Einstein tells us that clocks run slower the deeper they are in the gravitational potential well of a mass. This effect is described by General Relativity Theory as the gravitational red shift. General Relativity Theory also predicts that the rates of all clocks are equally influenced by gravitation independent of how these clocks are physically or technically constructed. However, more recent theories of gravitation...
New work from the Carnegie Institution’s Russell Hemley and Ivan Naumov hones in on the physics underlying the recently discovered fact that some metals stop being metallic under pressure. Metals are compounds that are capable of conducting the flow of electrons that make up an electric current.
Drizzling honey on toast can produce mesmerizing, meandering patterns, as the syrupy fluid ripples and coils in a sticky, golden thread. Dribbling paint on canvas can produce similarly serpentine loops and waves. The patterns created by such viscous fluids can be reproduced experimentally in a setup known as a “fluid mechanical sewing machine,” in which an overhead nozzle deposits a thick fluid onto a moving conveyor belt.
Modern research has found no simple, inexpensive way to alter a material’s thermal conductivity at room temperature. That lack of control has made it hard to create new classes of devices that use phonons, rather than electrons or photons, to harvest energy or transmit information. Phonons have proved hard to harness.
Light can come in many frequencies, only a small fraction of which can be seen by humans. Between the invisible low-frequency radio waves used by cell phones and the high frequencies associated with infrared light lies a fairly wide swath of the electromagnetic spectrum occupied by what are called terahertz, or sometimes submillimeter, waves.
Ultracold atoms in the so-called optical lattices, which are generated by crosswise superposition of laser beams, have proven to be one of the most promising tools for simulating and understanding the behavior of many-body systems. However, the implementation in free space has some limitations such as the distance between the atoms (around 400 nm) and the short range of the interactions.
Traps. Whether you’re squaring off against the Empire or trying to wring electricity out of sunlight, they’re almost never a good thing. But sometimes you can turn that trap to your advantage. A team from the Univ. of Nebraska-Lincoln, working with researchers at NIST, has shown that electron-trapping defects that are typically problematic in solar cells can be an asset when engineering sensitive light detectors.