A new study has investigated the effects of small but finite inertia on the propulsion of micro- and nano-scale swimming machines. Scientists have found that the direction of propulsion made possible by such inertia is opposite to that induced by a viscoelastic fluid. The findings could help to optimize the design of swimming machines to improve their mobility in medical applications.
Physicists have identified the “quantum glue” that underlies a promising type of...
With the help of ultracold quantum gas, physicists...
In findings that help astrophysicists understand our corner of the galaxy, an international research team has shown that the soft x-ray glow blanketing the sky comes from both inside and outside the solar system. The source of this "diffuse x-ray background" has been debated for the past 50 years.
A new method of building materials using light, developed by researchers at the Univ. of Cambridge, could one day enable technologies that are often considered the realm of science fiction. Although cloaked starships won’t be a reality for quite some time, the technique which researchers have developed for constructing materials with building blocks a few nanometers across can be used to control the way that light flies through them.
The magnets cluttering the face of your refrigerator may one day be used as cooling agents, according to a new theory. The theory describes the motion of magnons. In addition to magnetic moments, magnons also conduct heat; from their equations, the researchers found that when exposed to a magnetic field gradient, magnons may be driven to move from one end of a magnet to another, carrying heat with them and producing a cooling effect.
Using a new type of large-scale magnet conductor, scientists in Japan have recently achieved an electrical current of 100,000 A, a world record. The conductor, which was built using yttrium-based high-temperature superconducting tapes for high mechanical strength, is a prototype for using in a future fusion reactor.
A novel combination of microscopy and data processing has given researchers at Oak Ridge National Laboratory (ORNL) an unprecedented look at the surface of a material known for its unusual physical and electrochemical properties. The research team led by ORNL’s Zheng Gai examined how oxygen affects the surface of a perovskite manganite, a complex material that exhibits dramatic magnetic and electronic behavior.
Scientists at Northwestern Univ. have developed a new technique for creating non-equilibrium systems, which experience constant changes in energy and phases, such as temperature fluctuations, freezing and melting, or movement. The method, which involves injecting energy through oscillations to force particles to self-assemble under non-equilibrium conditions, should help us understand the fundamentals of this mysterious topic.
Research led by Penn State Univ. and Cornell Univ. physicists is studying "spintorque" in devices that combine a standard magnetic material with a new material known as a topological insulator. The new insulator, which is made of bismuth selenide and operates at room temperature, overcomes one of the key challenges to developing a spintronics technology based on spin-orbit coupling.
More than a decade ago, news of a Namibian desert beetle’s efficient water collection system inspired engineers to try and reproduce these surfaces in the laboratory. Small-scale advances in fluid physics, materials engineering and nanoscience since that time have brought them close to succeeding. And their work could have impact on a wide range of industries at the macroscale.
Researchers from NIST and California Institute of Technology (Caltech) have demonstrated a new design for an atomic clock that is based on a chip-scale frequency comb, or a microcomb. The microcomb clock, featured in Optica, is the first demonstration of all-optical control of the microcomb, and its accurate conversion of optical frequencies to lower microwave frequencies.
Spinach gave Popeye super strength, but it also holds the promise of a different power for a group of scientists: the ability to convert sunlight into a clean, efficient alternative fuel. Purdue Univ. physicists are part of an international group using spinach to study the proteins involved in photosynthesis, the process by which plants convert the sun’s energy into carbohydrates used to power cellular processes.
A team of Dartmouth scientists and their colleagues have devised a breakthrough laser that uses a single artificial atom to generate and emit particles of light—and may play a crucial role in the development of quantum computers, which are predicted to eventually outperform even today’s most powerful supercomputers.
Empty space is a bubbling soup of various virtual particles popping in and out of existence. Theorists from Austria and Vienna have recently proposed a way to amplify the force of these counter-intuitive phenomena called “vacuum fluctuations” by several orders of magnitude using a transmission line, channelling virtual photons. The strategy could have profound implications for understanding Casimir and Van der Waals forces.
Researchers in Spain have announced their successful effort to build a silicon 1-D optomechanical crystal so that it allows both phonons and photons to localize in a stable way. This marks an opportunity to study the interaction between electromagnetic radiation and mechanical vibrations of matter with a new level of precision.
Graphene, a material that consists of a lattice of carbon atoms, one atom thick, is widely touted as being the most electrically conductive material ever studied. However, not all graphene is the same. With so few atoms comprising the entirety of the material, the arrangement of each one has an impact on its overall function.
Applying just the right amount of tension to a chain of carbon atoms can turn it from a metallic conductor to an insulator, according to Rice Univ. scientists. Stretching the material known as carbyne by just 3% can begin to change its properties in ways that engineers might find useful for mechanically activated nanoscale electronics and optics.
Using two thin, tiny gold nanorods 10,000 times thinner than a human hair, researchers from the U.S. and Germany have succeeded in creating an adjustable filter for so-called circularly polarized light. This switch for nano-optics is made from two tiny gold rods that reversibly change their optical properties when specific DNA molecules are added.
Lawrence Livermore National Laboratory scientists for the first time have experimentally re-created the conditions that exist deep inside giant planets, such as Jupiter, Uranus and many of the planets recently discovered outside our solar system. Researchers can now re-create and accurately measure material properties that control how these planets evolve over time, information essential for understanding how these massive objects form.
Ultra-fast x-ray laser research led by Kansas State Univ. has provided scientists with a snapshot of a fundamental molecular phenomenon. The finding sheds new light on microscopic electron motion in molecules. The researchers measured at which distances between the two atoms the electron transfer can occur.
One of the major road blocks to the design and development of new, more efficient solar cells may have been cleared. Researchers with the Lawrence Berkeley National Laboratory have developed the first ab initio method for characterizing the properties of “hot carriers” in semiconductors. Hot carriers are electrical charge carriers with significantly higher energy than charge carriers at thermal equilibrium.
Biological physicists at Rice Univ. have succeeded in analyzing transmembrane protein folding in the same way they study the proteins’ free-floating, globular cousins. They have applied energy landscape theory to proteins that are hard to view because they are inside cell membranes. The method should increase the technique’s value to researchers who study proteins implicated in diseases and possibly in the creation of drugs to treat them.
A heat-sensing camera designed at Arizona State University has provided data to create the most detailed global map yet made of Martian surface properties. THEMIS, the nine-band visual and infrared camera on NASA’s Mars Odyssey orbiter, was used to create this map, which is now available online. And citizen scientists are invited to help make it even better.
One of the great, unanswered questions for space weather scientists is just what creates two gigantic donuts of radiation surrounding Earth, called the Van Allen radiation belts. Theories abound, but probes sent by NASA have recently provided the first really strong confirmation of what's happening. For the first time, scientists can explain how the electrons are accelerated up to nearly the speed of light.
Scientists in Texas have created a unique sensor that amplifies the optical signature of molecules by about 100 billion times. The new imaging method uses a form of Raman spectroscopy in combination with an intricate but mass reproducible optical amplifier. Newly published tests found the device could accurately identify the composition and structure of individual molecules containing fewer than 20 atoms.
Using a newly developed, ultrafast femtosecond infrared light source, chemists at the University of Chicago have been able to directly visualize the coordinated vibrations between hydrogen-bonded molecules. This marks the first time this sort of chemical interaction, which is found in nature everywhere at the molecular level, has been directly visualized.
Researchers at RIKEN in Japan, in collaboration with researchers from Purdue Univ., have recently demonstrated the scalability of quantum dot architectures by trapping and controlling four electrons in a single device. Circuits based on quantum dots are one of the most promising practical routes to harnessing the potential of quantum computing.
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