ARM shares boosted by Microsoft deal

Shares in Cambridge-based ARM rose more than 11% after the announcement on Friday of a licensing agreement with Microsoft.
The agreement extends a collaboration between ARM and Microsoft on software and devices for the embedded, consumer and mobile markets. The two companies have worked together since 1997.


The latest deal, which gives Microsoft access to Arm's core architecture, is thought to signal Arm's long-awaited breakthrough into the computer market, according to the Financial Times.
See also: Microsoft signs closer access to ARM IP

ARM's share price was further buoyed by speculation that Microsoft, which has designed its products around the chip architecture of Intel, will port Windows to work on ARM architecture.
Analysts also said Microsoft may develop its own applications processing chip for mobile devices and games consoles as Apple has done with the A4 chip used in the iPad and iPhone 4.
Microsoft is keen to strengthen its position in the mobile market as it prepares to launch its Phone 7 mobile operating system in August in the face of stiff competition from Android and iPhone.

Quantum Gas in Free Fall: Bose-Einstein Condensate at Zero Gravity

A sensitive measuring device must not be dropped -- because this usually destroys the precision of the instrument. A team of researchers including scientists from the Max Planck Institute of Quantum Optics has done exactly this, however. And the researchers want to use this experience to make the measuring instrument even more sensitive. The team, headed by physicists from the University of Hanover, dropped a piece of apparatus, in which they generated a weightless Bose-Einstein condensate (BEC), to the bottom of a drop tower at the University of Bremen.

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The particles in a BEC lose their individuality and can be considered to be a 'super-particle'. The researchers want to use such an ultra-cold quantum gas at zero gravity to construct a very sensitive measuring device for the Earth's gravitational field -- in order to find deposits of minerals, and also to settle fundamental issues in physics.

The research appears in the journal Science.

In a vacuum, a feather falls as quickly as a lead ball -- something that is already presented to students as being irrefutable. "However, the equivalence principle is only a postulate that needs to be tested," says Ernst Maria Rasel, professor at the University of Hanover. According to the equivalence principle, the heavy mass with which bodies attract each other corresponds to the inertial mass, which resists an accelerating force. This means that in a vacuum all bodies hit the ground with the same speed. Physicists want to use a measuring device that measures gravity extremely accurately to investigate whether this hypothesis can really become a physical law. Ernst Maria Rasel's team has now taken an initial step in this direction.

The researchers generated a Bose-Einstein condensate (BEC) in zero gravity and observed, for more than a second, how the atomic cloud behaves in free fall. To this end, they installed an atom chip developed by researchers working with Theodor W. Hänsch, Director at the Max Planck Institute of Quantum Optics, and solenoids, lasers, a camera and the necessary energy supply into a cylindrical capsule, which is about as high and wide as a door. After they had moved a cloud of several million rubidium atoms onto the atom chip, they dropped the complete apparatus 146 metres into the depths. A tower at the Center of Applied Space Technology and Microgravity of the University of Bremen specializes in such scientific cases.

As the capsule was falling to the ground for four seconds in the drop tower, the researchers generated the BEC on the atom chip, initially by remote control: strong magnetic fields and lasers hold the particles on the chip and cool them. At a few millionths of a degree above absolute zero, the temperature at minus 273.16 degrees Celsius, the particles have lost almost all of their energy and assume a new physical state: all atoms are now in the quantum mechanical ground state so that they can no longer be distinguished as individual particles in the quantum gas.

An atom chip -- the fast path to ultra-cold quantum gas

"They behave completely coherently, practically like a heap of atoms that assumes the properties of a single huge atom," says Tilo Steinmetz, who was involved in the experiment as a researcher from the Max Planck Institute of Quantum Optics. Since the laws of quantum mechanics say that every particle can also be considered to be a wave, it is possible to describe what is happening in a different way: A wave packet of matter forms in which the atoms no longer stay at fixed locations -- they are delocalized. This grouping is maintained until an energetic push, however small, mixes it up.

"We generate a BEC in less than a second on our atom chip. With conventional laboratory apparatus, this takes up to one minute," says Tilo Steinmetz. In addition, an experiment on an atom chip requires significantly less electrical power. "It is thus ideal for use in a drop tower capsule, where energy supply and cooling present a logistical challenge," says Steinmetz.

Ten times more time for a measurement

As soon as the atoms on the chip had merged into the super-particle, the researchers carefully loosened the hold of the trap and released the BEC. The camera in the capsule now enabled them to observe how the condensate spread. This movement reacts extremely sensitively to external fields -- to differences in Earth's gravitational field, for example. These differences exist because the gravitation at a certain point on Earth depends on the local density of the Earth's crust. The longer the Bose-Einstein condensate expands, i.e. the longer it floats in zero gravity, the clearer these differences make themselves felt as it expands. With the experiment in the drop tower alone, the researchers extended the time available for a measurement by more than tenfold when compared to a laboratory experiment. This could help in the future to drastically improve the accuracy of measurement data.

The differences can be measured in an atom interferometer: A quantum gas, that is the wave-packet of matter, is split into two parts and moves in the gravitational field along different paths through space-time. Gravitation behaves like an optical medium, whose refractive index refracts the waves. As soon as the two parts reunite, there is interference, as is also generated when waves on a water surface run into each other. The interference pattern depends on how differently the two matter waves expand. If matter waves of different composition are compared, a test of the equivalence principle with matter waves is performed. The physicists in Ernst Maria Rasel's group now want to construct such an atom interferometer for the capsule of the Bremen drop tower.

"Ultimately, we would like to perform such experiments in space," says Ernst Maria Rasel. The equivalence principle could also be tested there. To this end, the researchers must drop clouds of different atoms to Earth for as long as possible. They could then find out whether all bodies really fall with the same speed. And the longer the atom clouds remain in zero gravity -- that is, the further they fall -- the more chance there is of clarifying this.

Scientists Strive to Replace Silicon With Graphene on Nanocircuitry

Scientists have made a breakthrough toward creating nanocircuitry on graphene, widely regarded as the most promising candidate to replace silicon as the building block of transistors. They have devised a simple and quick one-step process based on thermochemical nanolithography (TCNL) for creating nanowires, tuning the electronic properties of reduced graphene oxide on the nanoscale and thereby allowing it to switch from being an insulating material to a conducting material.

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The technique works with multiple forms of graphene and is poised to become an important finding for the development of graphene electronics. The research appears in the June 11, 2010, issue of the journal Science.

Scientists who work with nanocircuits are enthusiastic about graphene because electrons meet with less resistance when they travel along graphene compared to silicon and because today's silicon transistors are nearly as small as allowed by the laws of physics. Graphene also has the edge due to its thickness -- it's a carbon sheet that is a single atom thick. While graphene nanoelectronics could be faster and consume less power than silicon, no one knew how to produce graphene nanostructures on such a reproducible or scalable method. That is until now.

"We've shown that by locally heating insulating graphene oxide, both the flakes and epitaxial varieties, with an atomic force microscope tip, we can write nanowires with dimensions down to 12 nanometers. And we can tune their electronic properties to be up to four orders of magnitude more conductive. We've seen no sign of tip wear or sample tearing," said Elisa Riedo, associate professor in the School of Physics at the Georgia Institute of Technology.

On the macroscale, the conductivity of graphene oxide can be changed from an insulating material to a more conductive graphene-like material using large furnaces.

Now, the research team used TCNL to increase the temperature of reduced graphene oxide at the nanoscale, so they can draw graphene-like nanocircuits. They found that when it reached 130 degrees Celsius, the reduced graphene oxide began to become more conductive.

"So the beauty of this is that we've devised a simple, robust and reproducible technique that enables us to change an insulating sample into a conducting nanowire. These properties are the hallmark of a productive technology," said Paul Sheehan, head of the Surface Nanoscience and Sensor Technology Section at the Naval Research Laboratory in Washington, D.C.

The research team tested two types of graphene oxide -- one made from silicon carbide, the other with graphite powder.

"I think there are three things about this study that make it stand out," said William P. King, associate professor in the Mechanical Science and Engineering department at the University of Illinois at Urbana-Champaign. "First, is that the entire process happens in one step. You go from insulating graphene oxide to a functional electronic material by simply applying a nano-heater. Second, we think that any type of graphene will behave this way. Third, the writing is an extremely fast technique. These nanostructures can be synthesized at such a high rate that the approach could be very useful for engineers who want to make nanocircuits."

"This project is an excellent example of the new technologies that epitaxial graphene electronics enables," said Walt de Heer, Regent's Professor in Georgia Tech's School of Physics and the original proponent of epitaxial graphene in electronics. His study led to the establishment of the Materials Research Science and Engineering Center two years ago. "The simple conversion from graphene oxide to graphene is an important and fast method to produce conducting wires. This method can be used not only for flexible electronics, but it is possible, sometime in the future, that the bio-compatible graphene wires can be used to measure electrical signals from single biological cells."

Worm's Eye View: Molecular Worm Algorithm Navigates Inside Chemical Labyrinth

With the passage of a molecule through the labyrinth of a chemical system being so critical to catalysis and other important chemical processes, computer simulations are frequently used to model potential molecule/labyrinth interactions. In the past, such simulations have been expensive and time-consuming to carry out, but now researchers with the Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a new algorithm that should make future simulations easier and faster to compute, and yield much more accurate results.

"Currently the major limiting factor in running molecular simulations for a large number of structures before they can be screened for useful materials is the need to visually analyze the structures to set up successful simulations," says Maciej Haranczyk, a computational chemist and a 2008 Glenn T. Seaborg Fellow in Berkeley Lab's Computational Research Division. "With our approach, such structural analysis can be done automatically, which speeds up the whole process of material screening."

Haranczyk is co-author of a paper that appears in the Proceedings of the National Academy of Sciences entitled: "Navigating molecular worms inside chemical labyrinths." The other author of this paper is James Sethian, who heads the Mathematics Group of Berkeley Lab's Computational Research Division, and is also a professor in the Mathematics Department of the University of California, Berkeley.

A key to the success of this new algorithm was its departure from the traditional treatment of molecules as hard spheres with fixed radii. Instead, Haranczyk and Sethian constructed "molecular worms" from blocks connected by flexible links. These molecular worms provide a more realistic depiction of a molecule's geometry, thereby providing a more accurate picture of how that molecule will navigate through a given chemical labyrinth, as Sethian explains.

"In practice, most molecules of interest, even the simplest solvents or gases, rarely have a spherical shape, and treating molecules as such may lead to errors," he says. "Our molecular worms are able to change shape during the traversing of a chemical labyrinth, which allows them to reach areas not accessible to either a single large spherical probe or a rigid real-shape probe. This significantly extends the range of probes and structures that can be efficiently examined."

As a molecule navigates through a chemical system, its access to a particular site or place within that system determines the extent to which catalysis and other chemical reactions may occur. Many of these critical sites are either buried in clefts, pockets or hidden cavities, or else represent channel systems. The accessible volume of a chemical system -- the free volume available to a penetrating molecule -- is also critical to the system's physical properties, including diffusion, viscosity and electrical conductivity. Predicting whether a molecule will be able to traverse through a given chemical labyrinth is the first question that a simulation must answer, followed by identifying the shortest transverse route, finding the largest probe that can transverse though the system, and calculating accessible volume.

"The required calculations become quite expensive as one needs to include interactions of all the atoms of the penetrating molecule with all the atoms in the labyrinth, and this procedure has to be repeated at every step of the simulation," Haranczyk says. "Additionally, in molecular dynamics only one trajectory per molecule is investigated. Since a penetrating molecule can be bouncing off the walls of a system before it finds a way out, mapping accessible volume in a chemical labyrinth may require the running of a very long simulation to actually see the molecule moving through."

Haranczyk, looking to automate the process by which the void spaces of porous materials are analyzed, had an idea for a probe that would walk through the inside a material and map it. Sethian had been working on mathematic techniques that can be used in robotic navigations and path planning, as well as a host of algorithms for computing geometries in complex settings.

"What's exciting here is to bring together two disparate worlds to build a new technology" says Sethian.

The two scientists pooled their expertise to develop the molecular worm algorithm, which they first tested on a zeolite material. Zeolites are microporous minerals that have been widely used since the late 1950s as chemical catalysts, membranes for separations, and water softeners. They are especially useful as alkane-cracking catalysts in oil refinement.

"There are 190 zeolite structures known to exist today, but they constitute only a very small fraction of the 2.5 million structures that are feasible on theoretical grounds," Haranczyk says. "The development of a database of hypothetical zeolite structures has long been regarded as an important step toward designer catalysts as it could, in principle, be screened for zeolites of any property. However, brute-force screening of all possible zeolite structures through molecular dynamics characterization is computationally infeasible, hence the need for rapid triaging based on an initial analysis of various properties."

The successful testing of the molecular worm algorithm on a typical alkane-cracking zeolite opens an immediate door to its use in screening for new zeolites as well as a wide variety of other porous materials. The algorithm should also prove valuable in the search for materials that can capture carbon emissions before they enter the atmosphere. With further refinements, it could also one day be applied to proteins, especially enzymes.

"Being at the frontier of science and solving a very complex problem that has not been addressed before is always very exciting," Haranczyk says.