A team of Massachusetts Institute of Technology researchers has used a novel material that’s just a few atoms thick to create devices that can harness or emit light. This proof-of-concept could lead to ultra-thin, lightweight and flexible photovoltaic cells, light-emitting diodes (LEDs) and other optoelectronic devices, they say.
A new mechanism of controlling magnetic states by electric currents has been discovered by an international team of researchers who have exploited a quantum phenomenon to control magnetic states with electrical currents. The research hinges on a quantum geometrical phase, called the Berry phase, that exists in the momentum space of electronic band structures in specific materials.
An experiment at SLAC National Accelerator Laboratory’s x-ray laser has revealed the first atomic-scale details of a new technique that could point the way to faster data storage in smartphones, laptops and other devices. Researchers used pulses of specially tuned light to change the magnetic properties of a material with potential for data storage.
Light can trigger coordinated, wave-like motions of atoms in atom-thin layers of crystal, scientists have shown. The waves, called phonon polaritons, are far shorter than light waves and can be "tuned" to particular frequencies and amplitudes by varying the number of layers of crystal, they report.
Flawed but colorful diamonds are among the most sensitive detectors of magnetic fields known today, allowing physicists to explore the minuscule magnetic fields in metals, exotic materials and even human tissue. A team of physicists have now shown that these diamond sensors can measure the tiny magnetic fields in high-temperature superconductors, providing a new tool to probe these much ballyhooed but poorly understood materials.
Sandia National Laboratories researchers Jim Martin and Kyle Solis have what Martin calls “a devil of a problem.” They’ve discovered how to harness magnetic fields to create vigorous, organized fluid flows in particle suspensions. The magnetically stimulated flows offer an alternative when heat transfer is difficult because they overcome natural convection limits.
Rice Univ. researchers have developed a theoretical approach to analyze the process by which protein building blocks form the biopolymer skeletons of living cells. The cytoskeleton, made of fibers and microtubules, gives a cell its shape and provides the “roads” along which proteins and other cargoes travel.
The USC Viterbi School of Engineering is home to the USC-Lockheed Martin Quantum Computing Center (QCC), a super-cooled, magnetically shielded facility specially built to house the first commercially available quantum computing processors. There are only two in use, and elaborate tests on the quantum processor, called D-Wave, indicate that it does use special laws of quantum mechanics to operate.
In physics, there's small, and then there's nullity, as in zero-dimensional. Univ. of Cincinnati researchers have reached this threshold with a special structure, zero-dimensional quantum dots, that may someday lead to better ways of harnessing solar energy, stronger lasers or more sensitive medical diagnostic devices.
An international team of researchers has used the world’s most powerful x-ray laser to take the first images of an ensemble of isolated molecules. The work, which took place at the Hamburg Center for Free-Electron Laser Science and choreographed a kind of molecular ballet in the x-ray beam, clears important hurdles on the way to x-ray images of individual molecules
U.K. scientists have succeeded in measuring how the surfaces of glassy materials flow like a liquid, even when they should be solid. A series of simple and elegant experiments were the solution to a problem that has been plaguing condensed matter physicists for the past 20 years. The finding has implications for thin-film coating designs.
Researchers from ETH Zurich and the Univ. of Tubingen in Europehave recently described a process that suppresses the formation of methane in soils that are rich in humic substances. The soils act as a battery, releasing to and accepting electrons from soil bacteria depending on the presence of oxygen. The study shows that electron transfer to and from humic substances is an important process with global implications for methane release.
Scientists in Switzerland have analyzed data collected at CERN’s Large Hadron Collider that offer a first-time observation of the polarization of the photon emitted in the weak decay of a bottom quark. This finding opens the way to future measurements, which may reveal a reality deeper than the one described by the present theory of elementary particles, the so-called Standard Model.
How heat flows at the nanoscale can be very different than at larger scales, and researchers are working to understand how these features affect the transport of the fundamental units of heat, called phonons. At Cornell Univ. scientists have invented a phonon spectrometer whose measurements are 10 times sharper than standard methods. This boosted sensitivity has uncovered never-before-seen effects of phonon transport.
JILA physicists used an ultrafast laser and help from German theorists to discover a new semiconductor quasiparticle, a handful of smaller particles that briefly condense into a liquid-like droplet. Quasiparticles are composites of smaller particles that can be created inside solid materials and act together in a predictable way.
Collaborative work by physicists has successfully "weighed" the mass of the electron 13 times more precisely than the best previous effort. The result, which could have an impact on our understanding of fundamental physical laws, was achieved using a method that could determine the presence of a mosquito on a jumbo jet just by weighing the airplane.
Standing in a full-body scanner at an airport isn’t fun, and the process adds time and stress to a journey. It also raises privacy concerns. But researchers now report making several key advances in terahertz wave sensor technology to create a more precise and direct method for using these waves to detect explosives from greater distances.
A Chinese-U.S. research team is exploring the use of metamaterials to create devices that manipulate sound in versatile and unprecedented ways. In a recently published paper, the team reports a simple design for a device, called an acoustic field rotator, which can twist wave fronts inside it so that they appear to be propagating from another direction.
The physical implementation of a full-scale universal quantum computer remains an extraordinary challenge for physicists, mainly because existing approaches lose their “quantum-ness” as they are scaled up. At the Joint Quantum Institute, a new modular architecture is being explored that offers scalability to large numbers of qubits, and its components have been tested and are available.
In a surprising new finding, researchers have discovered that bacterial movement is impeded in flowing water, enhancing the likelihood that the microbes will attach to surfaces. The new work could have implications for the study of marine ecosystems, and for our understanding of how infections take hold in medical devices.
From steel beams to plastic Lego bricks, building blocks come in many materials and all sizes. Today, science has opened the way to manufacturing at the nanoscale with biological materials. Potential applications range from medicine to optoelectronic devices. In a paper published in Soft Matter, scientists announced their discovery of a 2-D crystalline structure assembled from the outer shells of a virus.
While pursuing the goal of turning a cloud of ultracold atoms into a completely new kind of circuit element, physicists at NIST have demonstrated that such a cloud, known as a Bose-Einstein condensate, can display a sort of "memory." The findings pave the way for a host of novel devices based on "atomtronics," an emerging field that offers an alternative to conventional electronics.
In a recently published paper, researchers proposed an experiment that may close the last major loophole of Bell’s inequality, a 50-year-old theorem that, if violated by experiments, would mean that our universe is based not on the textbook laws of classical physics, but on the less-tangible probabilities of quantum mechanics. Such a quantum view would allow for seemingly counterintuitive phenomena such as entanglement.
Computers don’t need to be error-free. They just need to correct their errors reliably, which means that controlling a quantum system is crucial to the function of a quantum computer. A research team has now found a way to control the quantum system of a diamond which has a few nitrogen impurities. They have used the system to perform a logic operation and error correction in a quantum register made from nuclear spins of the gemstone.
A team of researchers has demonstrated a new type of holographic memory device that could provide unprecedented data storage capacity and data processing capabilities in electronic devices. The new type of memory device uses spin waves, a collective oscillation of spins in magnetic materials, instead of the optical beams.