Wednesday, June 27, 2012

#QUANTUM: "Leaps Enable Chip-Scale Spintronics"

Quantum computers promise to solve outstanding problems that cannot be addressed by conventional digital devices, by encoding superpositions of multiple data values all of which can be operated on in a single massively parallel quantum computation. Unfortunately, solid-state materials have yet to provide a rock-solid architecture for executing quantum computations. Now, however, labs in both the U.S. and Europe are reporting progress in casting quantum computations into gallium arsenide and silicon chips, respectively: R. Colin Johnson

Here is what EETimes says about solid-state quantum computers: Separate labs in the U.S. and Europe recently reported progress in adapting solid-state materials to store spintronic quantum states, a critical hurdle on the path to using spintronics in quantum computing.

Many researchers believe that spintronics for quantum computing is the most promising way forward for future computer chips, but few have reliably cast them into solid-state materials. Unfortunately, the most successful experiments today use ultra-cold gases to store quantum spin-states. However, semiconductor R&D labs worldwide are aiming to recast spintronics into traditional solid-state materials.

Researchers at the City College of New York (CCNY) and the University of California-Berkeley (UCB) reported success using laser light to encode the spin-state of atomic nuclei on gallium arsenide chips. Using a technique whereby a scanning laser defines the spin-states on a gallium arsenide chip, the researchers claim they can set-up the initial conditions for a quantum computation that can be quickly reconfigured after completion.

Separately, the current record holders for maintaining a quantum state in a solid-state material recently surpassed their own record, reporting encoded spin states that lasted over three minutes. The researchers at Simon Fraser University and Oxford University reported a 100-time improvement over their 2008 report of 1.75 seconds. Because their solid-state material is conventional silicon, professor Mike Thewalt at Simon Fraser (Canada) and professor John Morton at Oxford (U.K.) claim their technique could enable conventional CMOS manufacturing to eventually be harnessed for future quantum computers...
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