ScienceDaily: Physics News

Which qubit my dear? New method to distinguish between neighboring quantum bits

Tue, 18 Jun 2013 10:17:17 EDT

Researchers have proposed a new way to distinguish between quantum bits that are placed only a few nanometers apart in a silicon chip, taking them a step closer to the construction of a large-scale quantum computer. In a significant feat of atomic engineering, they were also able to read-out the spins of individual electrons on a cluster of phosphorus atoms that had been placed precisely in silicon.

Spot-welding graphene nanoribbons atom by atom

Thu, 13 Jun 2013 09:22:22 EDT

Scientists have created single atom contacts between gold and graphene nanoribbons.

Discovery of new material state counterintuitive to laws of physics

Wed, 12 Jun 2013 22:42:42 EDT

When you squeeze something, it gets smaller -- unless you're among a group of scientists who have seemingly defied the laws of physics and found a way to apply pressure to make a material expand instead of compress/contract.

New quantum dot technique combines best of optical and electron microscopy

Wed, 12 Jun 2013 17:33:33 EDT

Researchers have developed a new microscopy technique that uses a process similar to how an old tube television produces a picture to image nanoscale features. Combining the best features of optical and scanning electron microscopy, the fast, versatile, and high-resolution technique allows scientists to view surface and subsurface features potentially as small as 10 nanometers in size.

Molecular 'sieves' harness ultraviolet irradiation for greener power generation

Wed, 12 Jun 2013 09:36:36 EDT

New research shows that exposing polymer molecular sieve membranes to ultraviolet (UV) irradiation in the presence of oxygen produces highly permeable and selective membranes for more efficient molecular-level separation, an essential process in everything from water purification to controlling gas emissions.

Global quantum networks based on optical fibers: Scientists quantum mechanically couple atoms to glass fiber cables

Wed, 12 Jun 2013 09:35:35 EDT

Researchers have quantum mechanically couple atoms to glass fiber cables. Now, they have shown that their technique enables storage of quantum information over a sufficiently long period of time to realize global quantum networks based on optical fibers.

'Popcorn' particle pathways promise better lithium-ion batteries

Tue, 11 Jun 2013 08:22:22 EDT

Researchers have confirmed the particle-by-particle mechanism by which lithium ions move in and out of electrodes made of lithium iron phosphate, findings that could lead to better performance in lithium-ion batteries in electric vehicles, medical equipment and aircraft.

Testing artificial photosynthesis: Fully integrated microfluidic test-bed for solar-driven electrochemical energy conversion systems

Mon, 10 Jun 2013 13:32:32 EDT

Researchers have developed the first fully integrated microfluidic test-bed for evaluating and optimizing solar-driven electrochemical energy conversion systems. This test-bed system has already been used to study schemes for photovoltaic electrolysis of water, and can be readily adapted to study proposed artificial photosynthesis and fuel cell technologies.

Simple theory may explain mysterious dark matter

Mon, 10 Jun 2013 13:28:28 EDT

The reason dark matter, which makes up 85 percent of all the matter in the universe, is invisible could be because it possesses a rare, donut-shaped type of electromagnetism instead of the more exotic forces that have been proposed, according to an analysis by theoretic physicists.

World's first large(wafer)-scale production of III-V semiconductor nanowire

Mon, 10 Jun 2013 08:39:39 EDT

Researchers have developed large-scale heteroepitaxial growth III-V nanowires on a Si wafer.

Carbon nanotubes for molecular magnetic resonances

Sun, 09 Jun 2013 19:57:57 EDT

Researchers have developed a new technique for measuring very weak forces on a molecular scale. Thanks to the use of carbon nanotubes, they have achieved the highest level of sensitivity to date. These results open the door for magnetic resonance imaging of individual molecules.

Whispering light hears liquids talk

Fri, 07 Jun 2013 08:53:53 EDT

Researchers have developed optomechanical sensors in which extremely minute forces exerted by light are used to generate and control high-frequency mechanical vibrations of microscale and nanoscale devices that will help unlock vibrational secrets of chemical and biological samples at the nanoscale.

'Long-awaited explanation' for mysterious effects in high-temperature superconductors

Fri, 07 Jun 2013 08:53:53 EDT

A German-French research team has constructed a new model that explains how the so-called pseudogap state forms in high-temperature superconductors. The calculations predict two coexisting electron orders. Below a certain temperature, superconductors lose their electrical resistance and can conduct electricity without loss.

Spooky action put to order: Different types of 'entanglement' classified

Thu, 06 Jun 2013 15:47:47 EDT

A property known as "entanglement" is a fundamental characteristic of quantum mechanics. Physicists and mathematicians have now shown how different forms of this phenomenon can be efficiently and systematically classified into categories. The method should help to fully exploit the potential of novel quantum technologies.

Quantum teleportation between atomic systems over long distances

Thu, 06 Jun 2013 14:08:08 EDT

Researchers have been able to teleport information from light to light at a quantum level for several years. In 2006, researchers succeeded in teleporting between light and gas atoms. Now the research group has succeeded in teleporting information between two clouds of gas atoms and to carry out the teleportation -- not just one or a few times, but successfully every single time.

Second life for possible spintronic materials: Manganese, gallium nitride merged in uniform layer

Thu, 06 Jun 2013 11:20:20 EDT

Ten years ago, scientists were convinced that a combination of manganese and gallium nitride could be a key material to create spintronics, the next generation of electronic devices that operate on properties found at the nanoscale.

Resistivity switch is window to role of magnetism in iron-based superconductors

Wed, 05 Jun 2013 14:44:44 EDT

Physicists have discovered surprising changes in electrical resistivity in iron-based superconductors. The findings offer further evidence that magnetism and superconductivity are closely related in this class of novel superconductors.

Increased NMR/MRI sensitivity through hyperpolarization of nuclei in diamond

Wed, 05 Jun 2013 13:37:37 EDT

Researchers have demonstrated the first magnetically-controlled nearly complete hyperpolarization of the spins of carbon-13 nuclei located near synthetic defects in diamond crystals. This spin hyperpolarization, which can be carried out with refrigerator-style magnets at room temperature, enhances NMR/MRI sensitivity by many orders of magnitude.

First observation of spin Hall effect in a quantum gas is step toward 'atomtronics'

Wed, 05 Jun 2013 13:36:36 EDT

Researchers have reported the first observation of the spin Hall effect in a Bose-Einstein condensate.

Giant planets offer help in faster research on material surfaces

Wed, 05 Jun 2013 09:02:02 EDT

New, fast and accurate algorithm, based on the mathematical formalism used to model processes accompanying interaction of light with gas planet atmospheres, is a major step towards better understanding of physical and chemical properties of materials’ surfaces studied under laboratory conditions.

Spintronics approach enables new quantum technologies

Tue, 04 Jun 2013 15:33:33 EDT

Researchers highlight the power of emerging quantum technologies in two recent articles. New technologies exploit quantum mechanics, the physics that dominates the atomic world, to perform disparate tasks such as nanoscale temperature measurement and processing quantum information with lasers.

Bringing cheaper, 'greener' lighting to market with inkjet-printed hybrid quantum dot LEDs

Tue, 04 Jun 2013 13:54:54 EDT

It's not easy going green. For home lighting applications, organic light emitting diodes (OLEDs) hold the promise of being both environmentally friendly and versatile. Though not as efficient as regular light-emitting diodes (LEDs), they offer a wider range of material choices and are more energy efficient than traditional lights. OLEDs can also be applied to flexible surfaces, which may lead to lights or television displays that can be rolled up and stowed in a pocket.

Quantum model helps solve mysteries of water

Tue, 04 Jun 2013 11:34:34 EDT

Scientists have revealed a major breakthrough in the modeling of water that could shed light on its mysterious properties.

Scientists create novel silicon electrodes that improve lithium-ion batteries

Tue, 04 Jun 2013 09:47:47 EDT

Scientists have dramatically improved the performance of lithium-ion batteries by creating novel electrodes made of silicon and conducting polymer hydrogel, a spongy material similar to that used in contact lenses and other household products. The scientists developed a new technique for producing low-cost, silicon-based batteries with potential applications for a wide range of electrical devices.

Dense hydrogen in a new light

Mon, 03 Jun 2013 16:42:42 EDT

Hydrogen is the most abundant element in the universe. The way it responds under extreme pressures and temperatures is crucial to our understanding of matter and the nature of hydrogen-rich planets. New work using intense infrared radiation shines new light on this fundamental material at extreme pressures and reveals the details of a surprising new form of solid hydrogen.

Path to compact, robust sources for ultrashort laser pulses

Mon, 03 Jun 2013 13:53:53 EDT

Laser researchers are challenging a basic assumption of engineering: "You can't have it all." They have shown that for applications in biomedical optics, material processing, and communications, a new approach could deliver desired capabilities with no problematic tradeoffs: In compact, inexpensive, efficient and long-lived lasers that produce ultrashort, high-energy light pulses. They present experimental results with pulses as short as 60 picoseconds and predict that this technique will allow practical subpicosecond devices.

Cosmic rays: Galactic knee and extragalactic ankle

Mon, 03 Jun 2013 11:33:33 EDT

A new experiment has yielded the important result that a characteristic bend in the energy spectrum of high-energy cosmic rays, also called "knee", is located at different energies for light and heavy primary particles. Astronomers have found that these cosmic radiation particles are accelerated in galaxies other than the Milky Way.

Cool electron acceleration: Electron pulses from laser accelerator

Mon, 03 Jun 2013 11:33:33 EDT

Physicists have produced electron pulses from a laser accelerator whose individual particles all have nearly the same tuneable energy.

Magnetic monopoles erase data: Efficient and long-lived storage of information in magnetic vortices

Sun, 02 Jun 2013 20:39:39 EDT

A physical particle postulated 80 years ago, could provide a decisive step toward the realization of novel, highly efficient data storage devices. Scientists have found that with magnetic monopoles in magnetic vortices, called skyrmions, information can be written and erased.

Scientists capture first images of molecules before and after reaction

Thu, 30 May 2013 14:20:20 EDT

Using atomic force microscopy, chemists for the first time can capture images of molecules before and after they react, which will allow them to better tune reactions to get the products they want. Chemists and physicists joined forces to develop the technique, which could help scientists study and improve catalytic reactions like those used widely in industry to make chemicals or crack oil.

Atom by atom, bond by bond, a chemical reaction caught in the act

Thu, 30 May 2013 14:20:20 EDT

Scientists have produced remarkable images of carbon atoms and the bonds among them. Resembling glowing textbook diagrams, hydrocarbon molecules are shown in high resolution for the first time before and after bond-breaking, rearrangement, and reforming of bonds during a complex chemical reaction.

More precision from less predictability: A new quantum trade-off

Wed, 29 May 2013 19:10:10 EDT

Researchers in Australia have demonstrated that, contrary to what the Heisenberg uncertainty relation may suggest, particle properties such as position and momentum can be measured simultaneously with high precision. But it comes at a cost.

Discovery by physicists furthers understanding of superconductivity: Experiments show Zhang-Rice singlet state in different class of materials

Wed, 29 May 2013 12:10:10 EDT

Physicists have discovered that a crucial ingredient of high-temperature superconductivity could be found in an entirely different class of materials.

Klein tunneling: Coupled particles cross energy wall

Wed, 29 May 2013 09:22:22 EDT

A new model demonstrates that it is possible for two particles to cross an energy barrier together, where a single particle could not. For the first time, a new kind of so-called Klein tunneling -- representing the quantum equivalent of crossing an energy wall -- has been presented in a model of two interacting particles.

Just how secure is quantum cryptography?

Tue, 28 May 2013 12:24:24 EDT

Unlike classical encryption, quantum communication systems are known to offer the promise of virtually unbreakable encryption. Now, new research on this topic is shaking up the long-held notion that quantum communications are 100 percent secure. Researchers have recently demonstrated that quantum encryption may be susceptible to hacking.

Einstein's 'spooky action' common in large quantum systems

Tue, 28 May 2013 12:24:24 EDT

Mathematician have shown that entanglement -- what Einstein termed "spooky action at a distance" -- is actually prevalent in large quantum systems and have identified the threshold at which it occurs.

Have health effects from the Chernobyl accident been overestimated?

Tue, 28 May 2013 12:23:23 EDT

The impact of the Chernobyl nuclear accident has been seriously overestimated, while unfounded statements presented as scientific facts have been used to strangle the nuclear industry, according to Russian researchers. New research suggests that the health effects of food contamination in particular have been distorted in anti-industry propaganda.

Models from big molecules captured in a flash

Tue, 28 May 2013 10:02:02 EDT

The structures of most of the two million proteins in the human body are still unknown, even at low resolution. A new algorithm solves the convoluted shapes of large molecules by using images of numerous individual samples, all caught simultaneously in a split-second flash of x-rays from a free-electron laser. The technique promises efficient information about the shapes of many more large biological molecules in their native, fluid state.

Brittle material toughened: Tungsten-fiber-reinforced tungsten

Tue, 28 May 2013 09:16:16 EDT

Tungsten is particularly suitable as material for highly stressed parts of the vessel enclosing a hot fusion plasma, it being the metal with the highest melting point. A disadvantage, however, is its brittleness, which under stress makes it fragile and prone to damage. A novel, more resilient compound material has now been developed. It consists of homogeneous tungsten with coated tungsten wires embedded. A feasibility study has just shown the basic suitability of the new compound.

Hydrogen atoms under the magnifying glass: Nodal structures of electronic states of hydrogen atom directly observed

Mon, 27 May 2013 10:05:05 EDT

Researchers have succeeded in building a microscope that allows magnifying the wave function of excited electronic states of the hydrogen atom by a factor of more than 20,000, leading to a situation where the nodal structure of these electronic states can be visualized on a two-dimensional detector.

Helicopter light-beams: New tool for quantum optics

Mon, 27 May 2013 10:04:04 EDT

A light wave oscillates perpendicular to its propagation direction -- that is what students learn in school. However, scientists in Austria have now performed atomic physics experiments with light oscillating in the longitudinal direction.

Research effort deep underground could sort out cosmic-scale mysteries

Fri, 24 May 2013 13:43:43 EDT

Scientists have begun delivery of germanium-76 detectors to an underground laboratory in South Dakota in a team research effort that might explain the puzzling imbalance between matter and antimatter generated by the Big Bang.

The better to see you with: Scientists build record-setting metamaterial flat lens

Fri, 24 May 2013 13:17:17 EDT

For the first time, scientists working at the National Institute of Standards and Technology (NIST) have demonstrated a new type of lens that bends and focuses ultraviolet (UV) light in such an unusual way that it can create ghostly, 3D images of objects that float in free space. The easy-to-build lens could lead to improved photolithography, nanoscale manipulation and manufacturing, and even high-resolution three-dimensional imaging, as well as a number of as-yet-unimagined applications in a diverse range of fields.

Observation of skyrmions (magnetic vortex structures) in a ferromagnet with centrosymmetry

Fri, 24 May 2013 10:34:34 EDT

Researchers using Lorentz electron microscopy have shown that magnetic skyrmions are spontaneously formed as nanomagnetic clusters in a ferromagnetic manganese oxide with centrosymmetry.

Atomic-scale investigations solve key puzzle of LED efficiency

Thu, 23 May 2013 18:03:03 EDT

From the high-resolution glow of flat screen televisions to light bulbs that last for years, light-emitting diodes (LEDs) continue to transform technology. The celebrated efficiency and versatility of LEDs -- and other solid-state technologies including laser diodes and solar photovoltaics -- make them increasingly popular. Their full potential, however, remains untapped, in part because the semiconductor alloys that make these devices work continue to puzzle scientists. Scientists have now used electron microscopy imaging techniques to settle a solid-state controversy and raise new experimental possibilities.

Biophysicists measure mechanism that determines fate of living cells

Thu, 23 May 2013 14:37:37 EDT

For the first time, biophysicists have measured the molecular force required to mechanically transmit function-regulating signals within a cell. A new laboratory method, named the tension gauge tether approach, has made it possible to detect and measure the mechanics of the single-molecule interaction by which human cell receptors are activated.

A quantum simulator for magnetic materials

Thu, 23 May 2013 14:36:36 EDT

Physicists have developed a quantum simulator that allows arranging atoms in a way that they mimic the behavior of electrons in magnetic materials. The experiment opens up the possibility of systematically studying poorly understood properties of novel materials. The fresh insights might lead to designs for new magnetic materials.

Gold nanocrystal vibration captured on billion-frames-per-second film

Thu, 23 May 2013 14:35:35 EDT

A billon-frames-per-second film has captured the vibrations of gold nanocrystals in stunning detail for the first time.

Stitching defects into world’s thinnest semiconductor

Thu, 23 May 2013 11:38:38 EDT

Researchers have grown high-quality crystals of molybdenum disulfide, the world's thinnest semiconductor, and studied how these crystals stitch together at the atomic scale to form continuous sheets, gaining key insights into the optical and electronic properties of this new "wonder" material.

Quest for quantum computing advanced

Thu, 23 May 2013 08:29:29 EDT

Scientistst investigating the properties of ultra-thin films of new materials are helping bring quantum computing one step closer to reality.

Plasmonics: A wave without diffraction

Wed, 22 May 2013 13:10:10 EDT

Optical computing could benefit from the recent development of a novel electromagnetic wave.

Optics: Statistics light the way

Wed, 22 May 2013 13:10:10 EDT

A revelation of how photoreceptive cells in the eye distinguish between different light sources could pave the way for a novel class of optical devices.

New technique may open up an era of atomic-scale semiconductor devices

Wed, 22 May 2013 11:20:20 EDT

Researchers have developed a new technique for creating high-quality semiconductor thin films at the atomic scale -- meaning the films are only one atom thick. The technique can be used to create these thin films on a large scale, sufficient to coat wafers that are two inches wide, or larger.

New method for tailoring optical processors

Tue, 21 May 2013 12:16:16 EDT

Physicists and engineers have unveiled a robust new method for arranging metal nanoparticles in geometric patterns that can act as optical processors that transform incoming light signals into output of a different color.

Magnetic fingerprints of superfluid helium-3

Tue, 21 May 2013 10:54:54 EDT

Superconducting sensors have allowed for highly sensitive measurements of the nuclear magnetic resonance of thin helium-3 layers.

Coming into existence: Lab sets a new record for creating heralded photons

Mon, 20 May 2013 15:42:42 EDT

A new experiment establishes a heralding efficiency that might allow loopholes to be eliminated in the validation of spooky action-at-a-distance in quantum reality.

Nanoantennas improve infrared sensing

Mon, 20 May 2013 14:29:29 EDT

Engineers have used a pattern of nanoantennas to develop a new way of turning infrared light into mechanical action, opening the door to more sensitive infrared cameras and more compact chemical-analysis techniques.

Competition in the quantum world

Sun, 19 May 2013 19:48:48 EDT

Physicists have gained a deep insight into the nature of quantum mechanical phase transitions. Scientists have simulated the competition between two rival dynamical processes at a novel type of transition between two quantum mechanical orders.

Kinks and curves at the nanoscale: New research shows 'perfect twin boundaries' are not so perfect

Sun, 19 May 2013 19:04:04 EDT

Since 2004, materials scientists and nanotechnology experts have been excited about a special of arrangement of atoms called a "coherent twin boundary" that can add enormous strength to metals like gold and copper. The CTBs are described as "perfect," appearing like a one-atom-thick plane in models and images. New research shows that these boundaries are not perfect. Even more surprising, the newly discovered kinks and defects appear to be the cause of the CTB's strength.

World's smallest liquid droplets ever made in the lab, experiment suggests

Thu, 16 May 2013 20:06:06 EDT

Physicists may have created the smallest drops of liquid ever made in the lab. That possibility has been raised by the results of a recent experiment at the Large Hadron Collider, the world's largest and most powerful particle collider located at the European Laboratory for Nuclear and Particle Physics (CERN) in Switzerland. Evidence of the minuscule droplets was extracted from the results of colliding protons with lead ions at velocities approaching the speed of light.