Quantum computing has long been the fodder of science fiction novels. Mark Eriksson, a University of Wisconsin-Madison physics professor, hopes to make the concept the basis for non-fiction papers instead. He and his associates have developed a type of "quantum dot" device for holding electrons that can be scaled up to build a working quantum computer. Each quantum dot device contains just one electron. When the devices are aligned, the electrons they house become usable quantum bits, or qubits, for computing. The design incorporates a "back-gate" that serves as an electron reservoir, a quantum well that confines electrons vertically, and split "top gates" that provide lateral confinement by electrostatic repulsion. "The novel feature of our design," says Eriksson, "is the combined use of vertical tunnel coupling through the back gate, together with lateral coupling defined by the split top gates." To load a single electron into a dot, the gate potentials are adjusted so that single-electron filling is energetically favored. Unlike the bits of classical, serial computers, which exist in either the 0 or 1 state, qubits can exist in more than one state at once. This elusive quality of their components frees quantum computers to calculate all the possible solutions to a problem simultaneously, instead of running through them one-by-one like their slower, serial counterparts. This ability to parallel process means quantum computers hold tremendous number-crunching potential for certain tasks — such as highly sophisticated data encryption and code-breaking — that now defy even the most powerful computers. The group is in the beginning stages. "People often talk about quantum computing in the future tense, but that's not really right — it exists today. People have solved simple problems with it, but in the future we want to address problems that can't be solved by any other means," says Eriksson. For more information, contact Mark Eriksson either by phone (608) 263-2689 or e-mail firstname.lastname@example.org.
Samsung's Galaxy line of smartphones used to fare quite well in the repairability department, but last year's flagship S5 model took a tumble, scoring a meh-inducing 5/10. Will the newly redesigned S6 lead us back into star-studded territory, or will we sink further into the depths of a repairability black hole?
In 2003, the world contained just over 500 million Internet-connected devices. By 2010, this figure had risen to 12.5 billion connected objects, almost six devices per individual with access to the Internet. Now, as we move into 2015, the number of connected 'things' is expected to reach 25 billion, ultimately edging toward 50 billion by the end of the decade.
NASA engineer Brian Trease studied abroad in Japan as a high school student and used to fold fast-food wrappers into cranes using origami techniques he learned in library books. Inspired by this, he began to imagine that origami could be applied to building spacecraft components, particularly solar panels that could one day send solar power from space to be used on earth.
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