Posted: September 21, 2009 |
A tiny, tunable well of light, and a string theorist's toolbox |
(Nanowerk News) Photonics, the science of using photons to carry information, promises to continue improving a wide variety of technologies, from computing to high-speed communication. Now an international team of researchers from the UK, Taiwan, and Spain have discovered a compact way to produce infrared light, by firing electrons through a miniscule tunnel in a stack of gold and silica layers. The tiny, tunable light source could be the predecessor of a new component for light-based chips. The device is outlined in Physical Review Letters and highlighted with a Synopsis in the September 21, 2009 issue of Physics (physics.aps.org).
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A Toolbox for String Theorists
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A new toolkit of equations will help theorists determine whether a promising agreement between particle physics and string theory is fact or fancy. The research is reported in Physical Review Letters and accompanied by a Viewpoint in the September 21, 2009 issue of Physics.
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A novel design for a tunable source of infrared light relies on electrons fired into a tiny hole drilled through a stack of alternating gold and silica layers. (Image: G. Adamo, Optoelectronics Research Centre, University of Southampton)
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Physicists long for a single theory to describe the universe, but so far can't shoehorn Einstein's gravity and quantum mechanics into one elegant mathematical box. In 1997, a physicist named Juan Maldacena raised hopes of unification by proposing that the four-dimensional kingdom of a specific quantum theory was merely the border of a five-dimensional spacetime ruled by string theory. The possible harmony tantalized string theorists, but eluded proof, because the two theories were almost impossible to compare.
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Now Nikolay Gromov, Vladimir Kazakov, and Pedro Vieira have assembled a hefty toolbox of equations to help the thwarted string theorists tackle the question. With these tools in hand, theorists can measure the predictions of string theory against a slew of the quantum theory's results with unprecedented ease, placing them closer to finding out if Maldacena's idea is rock solid or the stuff of dreams.
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Also in Physics this week:
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Thierry Giamarchi writes a Viewpoint on a Physical Review Letters paper probing the cocktail of standard and exotic physics that governs the electrons in a ladder-like arrangement of molecules in a metal.
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