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sexta-feira, junho 25, 2010

'Quantum Computer' a Stage Closer With Silicon Breakthrough

ScienceDaily (June 23, 2010) — The remarkable ability of an electron to exist in two places at once has been controlled in the most common electronic material -- silicon -- for the first time. The research findings -- published in Nature by a UK-Dutch team from the University of Surrey, UCL (University College) London, Heriot-Watt University in Edinburgh, and the FOM Institute for Plasma Physics near Utrecht -- marks a significant step towards the making of an affordable "quantum computer."

The electron orbits a phosphorus atom embedded in the silicon lattice, shown in silver. The undisturbed electron density distribution, calculated from the quantum mechanical equations of motion is shown in yellow. A laser pulse can modify the electron’s state so that it has the density distribution shown in green. Our first laser pulse, arriving from the left, puts the electron into a superposition of both states, which we control with a second pulse, also from the left, to give a pulse which we detect, emerging to the right. The characteristics of this "echo" pulse tell us about the superposition we have made. (Credit: UCL)

According to the research paper, the scientists have created a simple version of Schrodinger's cat -- which is paradoxically simultaneously both dead and alive -- in the cheap and simple material out of which ordinary computer chips are made.

"This is a real breakthrough for modern electronics and has huge potential for the future," explained Professor Ben Murdin, Photonics Group Leader at the University of Surrey. "Lasers have had an ever increasing impact on technology, especially for the transmission of processed information between computers, and this development illustrates their potential power for processing information inside the computer itself. In our case we used a far-infrared, very short, high intensity pulse from the Dutch FELIX laser to put an electron orbiting within silicon into two states at once -- a so-called quantum superposition state. We then demonstrated that the superposition state could be controlled so that the electrons emit a burst of light at a well-defined time after the superposition was created. The burst of light is called a photon echo; and its observation proved we have full control over the quantum state of the atoms."
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Read more here/Leia mais aqui: Science Daily

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