Scientists at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California at Berkeley have performed the first scanning tunneling spectroscopy of graphene flakes equipped with a "gate" electrode. The result is the latest in a series of surprising insights into the electronic behavior of this unique, two-dimensional crystal form of carbon: an unexpected gap-like feature in the energy spectrum of electrons tunneling into graphene's single layer of atoms.

I first came across the word synchrotron in connection with the Crab Nebula, as well explained here at Hyperphysics. However, the phenomenon is these days very much down-to-earth: last weekend I returned from our last ever session at the Daresbury Synchrotron, which is soon to be shut down (final public use Saturday 1st August 2008). It first came on-line for experiments in 1981: prior to that, intense X-ray and hard UV synchrotron radiation was obtained as a by-product through “parasitic” operation on particle storage rings. Among others, Reading’s own Keith Codling had shown that much more useful science was being obtained from the synchrotron radiation than from the particle experiments. As a result of their concerted effort, the first Second-Generation light source was built at Daresbury.

By measuring a peak in the temperature of hot gas in the center of the giant elliptical galaxy NGC 4649, scientists have determined the mass of the galaxy's supermassive black hole. The method, applied for the first time, gives results that are consistent with a traditional technique.

Astronomers have been seeking different, independent ways of precisely weighing the largest supermassive black holes, that is, those that are billions of times more massive than the sun. Until now, methods based on observing the motions of stars or of gas in a disk near such large black holes had been used.

"This is tremendously important work since black holes can be elusive, and there are only a couple of ways to weigh them accurately," said Philip Humphrey, leader of the study and an assistant project scientist in the Department of Physics and Astronomy at UCI. David Buote, associate professor of physics and astronomy at UCI, also worked on this study.

Have you ever been puzzled by a statement like this: “Rotating a spin-1/2 particle by 360° does not bring it back to the same quantum state, but to the state with the opposite quantum phase; this is detectable, in principle, with interference experiments. To return the particle to its exact original state, one needs a 720° rotation.” (Wikipedia). Last week I zoomed back to 1820 and introduced Ørsted and his famous experiment, and left you with a promise of going mathematical tomb raiding. Tomb Raider was first released in 1996 for the Sega Saturn, and other platforms followed. The lore has it that this was the first mass market video game to be programmed using quaternions. Prior to that, rotations had been represented by Euler Angles or similar. Imagine you are flying an aeroplane. You are going in direction A, heading up or down at angle B, and your wings are tilted at angle C. Euler’s achievement in introducing these to the worlds of mechanics, astronomy, etc., in the mid-18th century was a landmark in itself. But they do come with mathematical problems when you are flying and tumbling at the speed of Lara Croft, one of which is that in certain orientations you can get a bad case of gimbal lock. Step in quaternions: the mathematical tomb raider who brought these to the worlds of video gaming and flight simulation appears to be Ken Shoemake, of the University of Pennsylvania, with a seminal paper in the journal Computer Graphics, 1985. But whom exactly did he, so to speak, “excavate”?

European researchers are the first to demonstrate functional components that exploit the magnetic properties of electrons to perform logic operations. Compatible with existing microtechnology, the new approach heralds the next era of faster, smaller and more efficient electronics.

In the 1960s, Henry Moore observed that it took around 18 months for silicon chip manufacturers to shrink their technology and fit twice as many transistors into the same area of silicon.

But Moore's Law is beginning to lose its hold. According to the International Technology Roadmap for Semiconductors (ITRS), devices based on silicon-only technology will soon reach the limits of miniaturization and power efficiency.

It’s Physics World time again, folks!

This month’s (July 2008) issue has a cover headline “On reflection: Symmetry and the Standard Model”, and a diagram of the 8-dimensional E8 group squashed flat like a beached jellyfish on the 2-dimensional page. The article itself (by Stephen Maxfield of Liverpool University) is as good a summary of the development the Standard Model as I’ve come across, and does serve to persuade me that those guys, by and large, really do know what they’re talking about. But what are they talking about?

We all know what happens when cars collide on the freeway or an anvil lands on Wile E. Coyote's head - physics at the macro level is predictable. But what about a single hydrogen atom and a lone molecule of deuterium, the smallest atom and one of the smallest molecules?

When an atom collides with a molecule, traditional wisdom said the atom had to strike one end of the molecule hard to deliver energy to it. People thought a glancing blow from an atom would be useless in terms of energy transfer, but that turns out not to be the case, according to the researchers.

Every atom or molecule, even if it has no charge, has electrostatic forces around it-sort of like the magnetic field of the Earth. Those chemical forces exert a pull on any other atom or molecule within range, trying to form a chemical bond.

When lasers illuminate material it usually warms up, so laser beams are used for cutting sheet steel, for welding or even as scalpels. But this effect can also be reversed. When the frequency of the laser beam makes the irradiated material just not absorbing its light and slightly more energy (of the photons, as physicists call the light particles) is needed for that, this photons “take” this missing energy from the oscillation energy of the material’s atoms.

Such oscillation energy (“phonons”) is equivalent to the vibration of atoms which is also called temperature and which is slightly reduced by this: the material is cooled down. A team of scientists from Technische Universität Dortmund and Ruhr-Universität Bochum has just carried out the first detailed experimental study regarding this process (known as “photoluminescence up-conversion”) in semiconductor nanostructures. Based on this, the development of a vibration-free cooling of semiconductors might be possible.

Researchers from the Physikalisches Institut of the University of Stuttgart have create entangled quantum states in diamond, which means there is finally a diamond men care about - namely the one that might some day be inside a quantum computer working at room temperature, a feat so far considered impossible for other materials.

While physicists have long described the world of atoms by quantum mechanics, one of its strangest characteristics, and the one that defies easy description, allows the linking of two objects without any noticeable interaction over a distance.

Einstein called this a 'spooky interaction.'

One of the most spectacular experiments based on this unusual entanglement characteristic is quantum teleportation, where the properties of one quantum object are transferred to another one at a remote location.

The last time you had a cappuccino, did you think 'I bet I can learn something about type-I superconductors here?' Well, a team of Ames Laboratory physicists did and have found that the bubble-like arrangement of magnetic domains in superconducting lead exhibits patterns that are very similar to everyday froths like soap foam or frothed milk on a fancy coffee.

The similarities between the polygonal-shaped patterns in conventional foams and "suprafroths," the patterns created by a magnetic field in a superconductor, establish suprafroths as a model system for the study of froths.

Ruslan Prozorov, Ames Laboratory physicist and primary investigator, discovered the suprafroth pattern last year, seeing an unexpected foam-like design when he applied a magnetic field to a lead sample in a magneto-optics system. Since the term "superfroth" was already in use for an unrelated product, Prozorov coined "suprafroths" in a nod to history: in the 1930s, superconductors were called "supraconductors."