Science & Technology News (575)
Posted: September 16, 2014 10:38AM
For thousands of years, humanity has been working to uncover the mysteries of Nature, and we are still at it. Recently special attention has been given to the skin of cephalopods, which can change in color as well as 'see' color. Researchers at Rice University have now recreated the color changing aspect of the skin to create a color display that matches the vividness of modern displays.
The pixels in the new display are comprised of several hundred aluminum nanorods, and the color of each pixel is determined by their length and spacing. Electron-beam deposition was used to create the precise arrangement of nanorods, which ensure that only one color is produced by the aluminum. Previous attempts to use aluminum nanoparticles like this resulted in more muted colors, as a wider range of frequencies were created and mixed together.
Among the potential uses of these arrays is replacing the dyes in LCD displays. Dyes can wear out over time from prolonged light exposure, but the physics involved with the nanorods will never fade. Also the light produced by the nanorods is naturally polarized, which means that one less polarizer would be needed in a display using them.
Source: Rice University
Posted: September 16, 2014 06:04AM
Everyday many of us walk and run without much thought, because our brains and bodies know what to do. Robots however are still learning these actions and researchers at MIT recently constructed and programmed a robot to run and even leap over objects in its path. The robot is designed to emulate the cheetah, but does not yet match its speed, having only sprinted at 10 MPH.
To achieve this speed, each leg of the robotic cheetah follows a bounding algorithm that determines the amount of force that is applied to the ground. To determine exactly how much force is applied, the researchers looked to sprinters who extend their stride by pushing against the ground hard enough, to extend their airtime. Such a force-based approach actually makes it easier for the robot to navigate rough terrain and does not require force sensors on the feet. Also by simply increasing the force applied to the ground, the robot can leap over obstacles in its path.
One thing about this robot that sets it apart from many other is that it is all electric, which counters the belief some have that only a loud gasoline engine can provide the necessary power. The next goal the researchers have is to actually get the robot galloping, which should be easy to do from its current, bounding gait.
Posted: September 15, 2014 02:08PM
In the 1960s we learned about the sound of silence and now we are learning what the sound of an atom is. An artificial atom more specifically, which releases its vibrational energy is released as a kind of quantum particle. Researchers at Chalmers University of Technology have recently built a device to couple acoustic waves with the artificial atom, an achievement that could lead to some very interesting effects.
Artificial atoms are actually circuits made of a superconducting material, but they behave like atoms with the ability to be charged with energy, and emit it as a particle. Normal atoms emit this energy as light, but the researchers designed the artificial atom to actually emit and absorb acoustic energy. This energy would be comprised of quantum particles representing the weakest detectable sound. The frequency used was 4.8 GHz, which is close to microwave frequencies for light, but in music would be roughly D28, or 20 octaves above the highest note on a grand piano.
The value of coupling an artificial atom to sound is that sound is easier to control; with how much slower it is than light. This slow speed also translates to a very small wavelength that can actually be smaller than the atom, unlike light waves which are larger. That smaller relative size makes the properties of the atom easier to control, which could prove useful in future quantum technologies.
Posted: September 15, 2014 09:14AM
Friction is an inescapable phenomenon of the Universe, for better or worse, and ways to control it are always important. Adding fluorine to some carbon-based materials, like Teflon, is the key to making some non-stick materials, so it made sense to expect graphene to also become non-stick, by adding fluorine atoms. As researchers at the University of Pennsylvania discovered though, the result of that added fluorine atoms was actually increased friction, not decreased.
The reason for investigating how to make graphene, an atom-thick sheet of carbon, non-stick is to use it as a coating to protect surfaces from normal wear and tear. As graphene is so thin and exceptionally strong, its use as a coating makes sense, and making it non-stick would make it even better. The Pennsylvania researchers were not the only group to create fluorinated graphene, and both groups reported the increase in friction, but the other group attributed it to an increase in stiffness. The Pennsylvania researchers were not satisfied with this explanation though, and started examining and modelling the energy levels of the material. On the macroscale, energy levels do not impact friction, but at the scale graphene exists, energy levels can be just as powerful as physical levels.
What they determined was that the fluorine atoms were introducing peaks to the material's electronic energy levels, making it very rough compared to pure graphene. All is not lost though, as a coating of high-friction graphene could have a use, and this research improves our understanding of graphene's surface properties.
Source: University of Pennsylvania
Posted: September 15, 2014 07:32AM
Graphene has a long list of special properties, including great conductivity, flexibility, and mechanical strength. Also on the list is the curios ability to block gases and liquids, except for water. Researchers at the University of Manchester, however, have discovered a way to make graphene oxide completely impermeable, which would have numerous implications.
The reason stacks of graphene sheets let water through has to do with how the water molecules interact with the sheets, causing capillaries to form that the molecules can slip through, and sometimes bring other molecules with them. This has obvious uses for water purification, but it could also be used to protect surfaces from corrosion, weather elements, and more, if only water could also be blocked. The Manchester researchers found that simple chemical processes could actually be used to close those capillaries in graphene oxide films, making them stronger and impermeable.
Demonstrating what is possible with this the researchers covered copper plates with their graphene paint, and showed that they could store strongly corrosive acids. Potentially it could also find use in electronics, shipbuilding, the nuclear industry, and even for improving the shelf life of medicines.
Source: University of Manchester
Posted: September 12, 2014 02:02PM
For years now, researchers have been working on quantum computers that, thanks to quantum mechanics, will be able to run algorithms no classical computer could complete, in a reasonable amount of time. So far though, no quantum computer has been built that actually surpasses its modern electronic counterparts. Thanks to researchers at the University of Bristol, University of Queensland, and Imperial College London though, that defeat of classic computers may be sooner than ever before.
The key to this defeat of classical computers is to successfully run a quantum algorithm they cannot. Recently MIT researchers developed an algorithm known as Boson Sampling, which uses single photons to sample an exponentially large probability distribution. A classical computer would find the same task to be extremely difficult. The catch for quantum computing is that producing the needed number of single photons is also difficult.
What the team of researchers recently discovered is that two-photon sources could be chained together to generate more of the single photons, using standard probabilistic methods. With that done, the researchers just needed to prove that this new photon source can solve the Boson Sampling algorithm, and with that, the last experimental hurdle for demonstrating the power of quantum computers should be overcome.
Source: University of Bristol
Posted: September 12, 2014 09:36AM
When multiple fields in science collide, crazy things can happen. Researchers at MIT and the University of Manchester have recently discovered a unique behavior of electrons in a superlattice of graphene and hexagonal boron nitride, which connects materials science, particle physics, relativity, and topology. What was actually observed though has, "no known analog in particle physics."
When electrons are exposed to an electric field, they will try to move and take the path of least resistance, which is in the direction of the field. This is true of traditional conductors and of graphene, which has the unique property of conducting electrons as though they were massless particles. When a layer of graphene is atop of layer of boron nitride however, the researchers observed the electrons actually moving in a perpendicular direction to the field. Normally a magnetic field would be required to alter the direction of an electrical current like this.
To make this phenomenon even weirder, the researchers also discovered that two electrical currents could flow perpendicular to the field, creating a "neutral, chargeless current," as the charges cancel each other out. This could possibly be exploited to improve the efficiency of computers as such a chargeless current would not lose much energy to heat. However, the researchers do point out that other parts of the system may offset those efficiency gains, so more work is required to determine how useful this would be. Even without that answer though, this is still a discovery that will impact our understanding of how the Universe works.
Posted: September 12, 2014 06:20AM
Since graphene was first discovered, there has been a rush to find other two-dimensional materials, and discover their properties. The hope is to find one with properties that can be put to use in future technologies. Researchers at Rice University have recently discovered that 2D phosphorus may be an ideal semiconductor for advanced computers.
Like graphene, 2D phosphorus has a hexagonal lattice, but instead of being a flat sheet, alternating atoms jut out above the plane. This results in a greater variation to any defects in the material, which results in a deeper bandgap and decreased performance for many other materials. In this case though, because it is all phosphorus, the defects actually do not negatively impact the material's electrical properties. This makes it a superior semiconductor to the 3D silicon currently used in electronics, as grain boundaries and point defects do not affect its properties.
Obviously one potential application of 2D phosphorus is future computer chip, but it could see use in many of places. One example would be for solar cells as its bandgap should respond well to the spectrum of sunlight.
Source: Rice University
Posted: September 11, 2014 02:02PM
More and more people want optics used to carry data across the nation and to their homes. This makes sense as photons can travel much faster and more efficiently than electrons, but they are still not as fast at carrying information as they could be. Researchers at the University of California, San Diego though have created a new photon switch that operates more than ten times faster than anything previously reported.
To achieve that amazing switching speed of 500 GHz, the researchers had to identify the ideal fiber for carrying the photons, develop a new means of measuring the fiber core, and determine the fewest number of photons needed to trigger the switch. The ideal material turned out to be silica fibers, as it has very little optical loss and kilometer-scale interaction lengths, but that is only half the work. The other half required analyzing the fiber core to profile its fluctuations over a great distance and with sub-nanometer precision. The method they developed is so precise that if a fly were land on the fiber miles away, the distortion to the fiber core would be measurable.
The precision of the fiber is matched by the efficiency of the 500 GHz switching. The researchers found that 2.5 picosecond pulses containing just three photons would be enough to control the light pulses, at that switching speed.
Posted: September 11, 2014 10:10AM
On its own, bread is nice, and on their own, cold cuts, hamburgers, sausages, peanut butter and jelly are nice, but combining them can give us something even better. (They can also make me hungry as I write about them.) Just as this is true for foods, advanced materials can also become more than what they were before when sandwiched together. Researchers at the University of Manchester have recently found that by manipulating a sandwich of graphene and white graphene, it is possible to tune the properties of the resulting crystal.
Graphene is an atom-thick sheet of carbon that is extraordinarily conductive, while so-called white graphene, hexagonal boron nitride (hBN) is actually a semiconductor. Some are hopeful that combinations of these two materials could result in new materials with superior properties to both, which could then be used in electronics. What the Manchester researchers have found is that when hBN is sandwiched between layers of graphene, the properties of the resulting hetrostructure can be controlled by altering the alignment of the layers.
With careful alignment of the graphene layers, conservation of energy and momentum can be achieved, which could allow for devices to operate with ultra-high frequencies. The next step, according to the researchers, is for someone to find a way to produce these multilayer materials using growth methods, instead of mechanical transfer.
Source: University of Manchester
Posted: September 11, 2014 06:15AM
Graphene has often been described as a material that could revolutionize many technologies, but so far it has yet to escape the lab and enter consumer products. Thanks to a partnership between the University of Cambridge and Plastic Logic though, that may change sooner than ever. Together the two organizations have created a flexible display that uses graphene for its electrodes.
Graphene is an atom-thick sheet of carbon atoms that has extraordinary electrical and physical properties, including being strong, flexible, transparent, and highly conductive. All of these contribute to why we want to see it used in our devices. The prototype display uses solution-processed graphene electrodes to replace the sputtered metal electrodes normally found in Plastic Logic's devices. This allows the display to be more flexible than if indium tin oxide were used, and more transparent than metal films would allow. It was also created at temperatures below 100 ºC.
The display itself may not be impressive beyond its flexibility and use of graphene, as it is only150 ppi and monochrome, like ereader displays. However the researchers are working to achieve full color and video by incorporating LCD or and OLED technologies.
Source: Rice University
Posted: September 10, 2014 02:33PM
Drums are an important part of any orchestra and each one fills a specific role, based on its mechanical properties. Thanks to researchers at the Delft University of Technology, drums, though not of the musical kind, could see an interesting use in future quantum computers.
The drum in question is a multilayer sheet of graphene covering a hole in a silicon chip just four microns wide. What makes the drum special is that next to it is a superconducting microwave cavity. This cavity produces microwave photons that can move between the two structures and actually beat the drum. This beating is possible because photons do carry a small amount of momentum, despite being massless. In the macroscopic world, this momentum does not have much of an impact, but it is enough to move the very light sheet of graphene. Provided the movement is greater than 17 femtometers, (approximately ten thousand times smaller than the diameter of an atom) it can be measured by the interference of the photons reflecting off of it.
This is the first time a mechanical resonator has been shown to be coupled to a superconducting microwave cavity, and such a setup could have many uses, such as amplifying microwave signals and even storing microwave signals for up to 10 ms. It could also be used as RAM for quantum computers, by having the drum enter a superposition with its beat, being both up and down at the same time.
Source: Institute of Physics
Posted: September 10, 2014 10:48AM
One of the consequences of the recent switch over from analog to digital of broadcast television was an opening up of spectrum blocks. Some hope to use these now available frequencies to serve wireless data over large areas, but typically increased range means decreased speed. By applying some modern wireless transmission methods, Rice University researchers hope to reach an acceptable balance.
One of the technologies being employed is MIMO or multiple-input, multiple-output, which uses multiple antennae to increase data rates without using for channels or power. This is a somewhat standard technology now that many devices now use. It is not enough to reach the needed balance though, which is why the Rice researchers developed the first open-source multiuser MIMO system. Instead of using the technology to provide a single user a better experience on a single channel, this multiuser system would serve multiple users all on the same channel.
The researchers have already tested their multiuser MIMO UHF system against 2.4 GHz and 5.8 GHz WiFi in both indoor and outdoor environments. The new system performed well with low-overhead wireless access and high spectral efficiency.
Source: Rice University
Posted: September 10, 2014 08:35AM
Weight is a problem for many people, and for those that reach the obese levels it can also become a health hazard with increased risk for multiple illnesses. To address the issue, researchers have been devising many new strategies, and those at Imperial College London are suggesting that social media be leveraged to help people lose weight.
Instead of generating new data through new experiments, the researchers analyzed 12 studies from the US, Europe, east Asia, and Australia. All of these studies were examining how social networking could be used to encourage and support weight loss, and combined had 1884 participants. The ICL researchers compiled the data and found that those who used the social networking services saw a BMI decrease of 0.64. While that value is only modest, it is significant and is definitely an encouraging sign of what could be accomplished.
The idea behind social media for weight loss is to build a network of clinicians and peers that support efforts to lose weight. While you do potentially have reduced costs, thanks to less travel and more people served at once, there are potential privacy issues that will likely have to be addressed. Still, this shows that there is another tool that can be used to fight obesity and the associated illnesses.
Source: Imperial College London
Posted: September 9, 2014 04:24PM
Thousands of years ago, humanity discovered how to create metallic alloys, which can often have properties superior to the original materials used. One example would be bronze, which is stronger than the copper that it is largely comprised of. Now researchers at Berkeley Lab and ORNL have discovered a new high-entropy alloy that could be of special use in extremely cold situations.
Typically alloys are composed of a few elements, with one representing the primary component, such as copper in bronze and iron in steel. High-entropy alloys however are made of multiple elements, and none is more dominant than another, and it has been theorized that such a material would have special properties. The Berkeley and ORNL researchers have put that to the test with CrMnFeCoNi (chromium, manganese, iron, cobalt, and nickel) and were actually surprised by the results. The alloy's tensile strength and fracture toughness are among some of the highest values ever recorded, and actually improve at cryogenic temperatures. The researchers believe it is because of a phenomenon called 'nano-twinning' which involves deformations in one crystalline region to be mirrored in another. This causes continuous strain hardening, which protects against premature failing.
This unique improvement at cryogenic temperature makes the alloy of great interest for making storage tanks for liquefied natural gas, hydrogen, and oxygen. These special mechanical properties have not been optimized yet, so CrMnFeCoNi may improve as research continues.
Source: Berkeley Lab
Posted: September 9, 2014 12:36PM
Author: Brentt Moore
Nest Labs has publically revealed that more products than ever are now compatible with its own lineup of devices. Thanks to the “Works with Nest” developer program, which was announced last year, all Nest products are now compatible with Control4, Crestron, Dropcam, Remote Technologies Incorporated, and Universal Remote Control. Due to the announcement, Dropcam, which was purchased by Nest earlier this year, automates the process of recording and saving video clips when triggered by Nest Protect, a smoke and carbon monoxide alarm currently offered by Nest. According to Nest founder Matt Rogers, "Professional installers are a key market partner for Nest and we’re committed to enabling our products to connect with the home automation systems they trust and install every day.”
Source: The Verge
Posted: September 9, 2014 09:44AM
That wonder material, graphene has many amazing electrical properties to it, but before it can be used, certain advancements need to be made. Researchers at EMPA have just made one by successfully creating heterojunctions within graphene nanoribbons. The researchers were also able to transfer the graphene piece from a conductive gold substrate to another, nonconductive material, which is vitally important for use in electronics.
Normally graphene, an atom-thick sheet of carbon atoms, is a conductor capable of carrying electrons at very high speeds, but when prepared as ultra-narrow nanoribbons, it becomes a semicondudctor. Semiconductors have what is known as a bandgap, which allows them to be switched from a conductive to a nonconductive state, and that is a needed feature for use in electronic circuits. What the EMPA researchers have discovered is that it is possible to dope graphene nanoribbons with nitrogen atoms and combine them with pure-graphene nanoribbons. This results in a p-n junction, as the nitrogen atoms introduce additional electrons, giving part of the nanoribbon a negative charge, while the remainder has a relative positive charge. This structure forces currents to only flow in one direction.
This kind of junction is a basic building block for many, more advanced electronic structures, such as transistors. The researchers estimate we will not see graphene nanoribbons used to create electronic switches in products for over a decade, but this work is bringing that day closer.
Posted: September 9, 2014 07:03AM
Many researchers have the goal of recreating something in Nature, such as the cells that living creatures are comprised of. Modern cells are very complex though, which is why researchers at Technische Universitaet Muenchen decided to look to what primordial cells were like, with the hope of one day building to complexity from simpler parts. Recently one of these simple parts achieved the ability to move on its own, which is a first for an artificial cytoskeleton membrane.
The earliest cells were just membranes with a few molecules inside, which is a functional if simple design. What the researchers created has a membrane similar to modern cells, with vesicals of microtubules, and kinesin moecules. Kinesins act as molecular motors in real cells, moving particles around along microtubules. In the artificial cell though, they instead move bundles of microtubules around, creating a constantly moving liquid crystal layer under the membrane. Thanks to a piece of mathematics figuratively called the 'hairy ball' theorem, we know that there must be a point that a bundle of microtubules are perpendicular to the other bundles, and the membrane. By varying the water content of the cell through osmosis, causing the membrane to collapse, and spiked extensions to form. These spikes, like those of living cells, can be used for movement.
Thanks to the minimalistic approach used here, this cell model could be used in the future to recreate living cells with a modular approach. Also, because the behavior of the artificial cell can be described by physics, it could be used to improve our understanding of how cells deform.
Source: Technische Universitaet Muenchen
Posted: September 8, 2014 02:04PM
Electrons and photons are two particles that are commonly used to transmit information, and each has its own advantages and disadvantages. Electrons are slower the photons, for example, but at small scales, electrons are decidedly easier to work with and manipulate. By using plasmons though, one could get the best of both worlds, and researchers at the University of Rochester have made a discovery that could have quite an impact.
The researchers discovered a curious interaction between a silver nanowire and the thin layer of molybdenum disulfide (MoS2) it was placed on. When a laser was aimed at the nanowire, plasmons were created on the wire, which then travelled along the wire and caused the MoS2 to emit the absorbed photons at the far end of the wire. The researchers also found that excited electrons within the MoS2 were entering the nanowire, where they became plasmons that then traveled back along the wire, to emit light of the same wavelength.
Normally plasmons do not get very far before they lose a substantial amount of energy, but in this experiment they had enough energy to make a round-trip on the wire. Such an accomplishment could prove invaluable for integrating high-speed photonic circuits onto semiconductor chips, by enabling an efficiency means for guiding light through the circuit.
Source: University of Rochester
Posted: September 8, 2014 06:13AM
Part of what makes social networks appealing to many people is their ability to connect people from various groups, who can then share opinions and information with each other. With so many people in a network though, an easy question to ask is how can they ever form a consensus? That is what researchers at the University of Miami have been wondering, so they developed a new model to describe the process.
For consensus to be reached, opinions will have to be changed to a degree, and the agents of these changes can be other people, sensors, databases, or abstract entities. While hard, empirical data can be easily analyzed and processed in a model, opinions or soft data are much trickier to interpret. To account for this, the new model uses a 'belief updating mechanism,' unlike previous studies that were dependent on how agents change their opinions, which would mean that different updating schemes would change a model's results. Instead this model considers how close an agent's opinion is to the consensus opinion, in order to judge credibility.
One advantage to this approach is that the model works even when the ground truth is not available to the network, attempting to reach a consensus concerning the truth. Next the researchers want to expand the model to consider the formation of opinion clusters, in which the agents share similar opinions.
Source: University of Miami
Posted: September 5, 2014 02:37PM
Thanks to our understanding of the bacteria E. coli, it has been given a tremendous number of uses, beyond food poisoning. It appears another ability can be added to the list, as researchers at Imperial College London and the University of Turku have successfully used the bacterium to create propane. Normally this hydrocarbon is acquired from oil and natural gas wells and could be used as a fuel.
Many processes are required for a cell to survive, and we have learned how to manipulate those processes well in E. coli. In this case the researchers interrupted the mechanism that converts fatty acids into cell membranes using a variant of a particular enzyme. This resulted in the butyric acid, which is a precursor for propane production. With another enzyme the acid was converted into butyraldehyde, and a final enzyme called ADO was then used to actually create the propane. Previous attempts to use ADO to create chemical fuels were disappointing, but the researchers found that stimulating it with electrons increased production.
Currently this research is just proof-of-concept, as little propane was actually produced. With additional work though, the researchers hope to refine their synthetic process and make it a commercially viable source of propane.
Source: Imperial College London
Posted: September 5, 2014 09:38AM
The largest land animal alive today is the African elephant and comes in at about 11 feet tall and 5.5 tons. While that is definitely quite big, there have been larger, especially when dinosaurs still dominated the planet. Researchers, including some from the National Science Foundation, have recently discovered and identified a gigantic dinosaur that would have weighed as much as 65 tons.
The bones of Dreadnoughtus schrani were discovered in Argentina across multiple expeditions from 2005 through 2009, and, surprisingly, constitute 70% of the full skeleton. Such complete skeletons are very rare to find and actually make this the largest land animal that we can accurately calculate body mass for. With such a complete specimen, a great deal can be learned about the anatomy and biomechanics of this and other large animals. One thing we know already about this 85-foot long behemoth is that this particular skeleton is from a dinosaur that was not full grown when it died. It is also a member of the titanosaurs, which is a group of large plant eaters.
Source: National Science Foundation
Posted: September 5, 2014 07:05AM
Unless you recently moved, there is a good chance you know your street address pretty well, but how about your address in the Universe? We should all know we are in the Milky Way galaxy and some of us likely know we are the Local Group galaxy cluster. Until now though we have not been sure about which galactic supercluster we call home, but researchers using the NSF's Green Bank Telescope (GBT) have recently completed a survey that answers the question.
Galactic clusters are often comprised of about a dozen galaxies that are gravitationally linked together. A supercluster can contain hundreds of these clusters, making them among the largest structures in the Universe. Due to their immense size, it is difficult to know their exact boundaries, but the researchers using the GBT came up with a new way to find them. This method involves measuring the velocities of galaxies, to determine how other structures impact their movement, and the supercluster with the greatest impact must be the galaxy's home.
The result of this work is the identification of the Laniakea supercluster, which is Hawaiian for "immense heaven." Our own galaxy is near the edge of this supercluster, which is 500 million light years across, and contains 100,000 galaxies totaling roughly one hundred quadrillion solar masses. Previously it was believed that we were a part of the Virgo supercluster, which is now just a part of the Laniakea supercluster.
Posted: September 4, 2014 09:16AM
There are some places where power is not available, but where we need to place an energy-using device. In some cases the device can use solar power or even harvest energy from radio waves, but neither is possible in some locations, like inside structures. Researchers at the University of Washington however, have developed a new device that could operate in these places, by converting temperature changes to electricity.
The idea the researchers are using was developed centuries ago to power a clock and exploits pressure changes due to pressure. When gases are heated, they will expand and exert a force that can be converted into electricity. In version of the technology, the temperature sensitive gas is contained in a metal bellows, which expands and contracts with temperature changes around it. Small cantilevers capture this motion to generate enough electricity to power sensors and a wireless transmitter. Just a 0.25 ºC change is enough to send a signal five meters to a receiver.
The researchers see this device being used to monitor buildings for water leaks and weaknesses inside of walls. Changes in temperature from the building's air conditioning or from the course of the day, would be sufficient to power the sensor.
Source: University of Washington
Posted: September 4, 2014 06:50AM
Modern electronics are based on the charge of electrons, but in the future devices that operate on another property, called spin, could become the new standard. Spin is not as easy to work with though, as special materials and conditions can be required to do so. Researchers at the Johannes Gutenberg Universitaet Mainz and others from around the world however have discovered how to create a spin-charge converter with gallium arsenide (GaAs) that operates at room temperature.
Part of what makes working with spin difficult is that magnetic fields are often required, as opposed to electric fields. A spin-charge converter is able to convert charge currents to spin currents and back, which would allow electric fields to be used. The catch is that previously only platinum, a rare heavy metal, had been identified as a viable material for creating a converter. By discovering that GaAs can also be used, spintronics are significantly closer to reality.
As it turns out, the advantages of GaAs are not limited to being cheaper and already widely used. The researchers found that it is possible to tune the efficiency of the converter and move the spin currents between different lanes, by varying the strength of the applied electric field.
Posted: September 3, 2014 02:10PM
Everybody is stressed at some point and for some reason, and how we manage that stress can be very important for our health. To help reduce stress, researchers at the University of Southampton have created an Android app to see if managing notifications can help manage stress.
The app is named Healthy Mind and will periodically provide the user with a notification about stress management, and, if opened, will provide more information. Exactly when the notification will appear is based on time of day, physical activity, and location, which is data the app monitors. The app is currently available on the Google Play store in the My Life Guide Toolbox and those who install it will be asked to join the five month study. For those that agree, they will be placed into one of three groups. One group will receive up to three notifications a day, based on the collected data, while the other two groups will receive one a day from 5 PM to 8 PM, or two a week, again from 5 PM to 8 PM.
Part of the thinking behind this app and study is that most people who are stressed do not seek professional help, but have their smartphones with them constantly. By leveraging the technology at our fingertips, the researchers hope to help people with stress.
Source: University of Southampton
Posted: September 3, 2014 06:16AM
In general, things are easier to manage when they are not moving but getting things to stop is not always that easy. This is as true of quantum mechanical particles as it is cars and children on a sugar-high, but you cannot grab onto a molecule and hold it still. Researchers at Northwestern University though, have found a way to start the tumbling of molecules, which could have implications for future quantum computers.
Over the decades, researchers have gotten pretty good at controlling atoms, but larger, more complex molecules are a different matter. Typically when you trap molecules, they will continue to rotate as though they were still freely moving, and some methods to stop them require cryostats to bring the temperature down to nearly absolute zero. The Northwestern researchers have instead developed a broadband laser that can stop a molecule in a fraction of a second. The key was in selecting the correct frequencies to cool the aluminum monohydride molecule down to just 4 K and its ground state, from room temperature. Shining a laser on molecules may not seem like a way to reduce the molecules' energy, but because of how the light frequencies interact with molecules, it is possible.
This new and elegant solution for bringing molecules to their ground state will likely see some use in quantum computing, but it does have other applications. Ultracold quantum-controlled chemistry could use the ability to control molecular rotors like this, and ground-state molecules could be used for testing if fundamental constants are constant throughout time.
Posted: September 2, 2014 02:11PM
They say you cannot judge a book by its cover, and that is just as true with materials as it is with literature. A material's surface definitely has an important influence on how it interacts with other materials, but materials can interact with more than external materials. Researchers at MIT are investigating how patterning the interfaces within materials can be used to shape their properties.
Traditionally materials have been considered as having an external surface and an interior bulk, but treating the bulk as containing its own surfaces, or interfaces, is a novel idea. To do this the researchers had to adapt equations for determining surface properties to describe how a surface can vary at different locations. Such work is difficult to do experimentally, but computer simulations are capable of it.
By controlling the within a material, the researchers envision the possibility of building altering a material's strength as well as building in useful features. One example would be properties to control the flow of heat and sound through a material, which would impact thermoelectrics, and another would be putting channels inside of shielding meant for nuclear fusion reactors, so that helium atoms could escape, rather than damage the shielding.
Posted: September 2, 2014 09:04AM
Currently most technology relies on electrons for carrying information, but many foresee a future where photons do that job instead. Transitioning from electronics to photonics is not going to be easy though in part because electrons and photons are such different quantum particles. Researchers at the Niels Bohr Institute however have developed a new photon cannon that overcomes one challenge, by producing single photons that travel in one direction.
The reason it is so difficult to produce single photons compared to electrons has to do with the types of particles they are. Electrons are fermions, which cannot group up, while photons are bosons that are very comfortable existing in the same place at the same time. By using a quantum dot, a synthesized semiconductor crystal though, the researchers are able to produce single photons by exciting the dot with a laser. While that addresses the single-photon issue, the photons are only useful if they go in the right direction. To accomplish that, the researchers built the dot in a photonic crystal on a chip, and that crystal forces the photons to go one way.
The resulting photon cannon the researchers built has a 98.4% success rate of producing single photons and having them go where they want to. Now the researchers are working to patent this work and develop high-efficiency prototypes that could see use for encryption and quantum computing.
Source: University of Copenhagen
Posted: September 2, 2014 06:32AM
Author: Brentt Moore
Smart Home, a technology offered by Samsung that connects all types of home electronics onto a single network for simplified access and control, is expected to have improved compatibility in the near future. Samsung plans to open the service up to third-party developers, allowing appliances and electronics to be controlled from Galaxy smartphones and company smartwatches. Although Samsung did not reveal specific third-party products or services that are expected to be compatible with Smart Home, it did tease capabilities such as monitoring the amount of electricity used by appliances, monitoring security cameras from a smartphone, and turning on lights by using geolocation. The expansion of Smart Home will be facilitated by a software development kit for the service that is expected to be released later this year.
More information about Smart Home will likely be revealed at the Samsung's Developer Conference, which begins on November 11, 2014.