I've been in IT for a long time by now and I read a lot about new and future technologies. One which fascinates me is the race for quantum computers.
These systems will use quantum bits, or qubits. Qubits are able to live simultaneously in 0 and 1 states. I can understand this -- from an intellectual point of view. But it's different on a practical one.
Anyway, let's jump to the EE Times article.
Researchers at the University of Wisconsin in Madison claim to have created the world's first successful simulation of a quantum-computer architecture that uses existing silicon fabrication techniques. By harnessing both vertical and horizontal tunneling through dual top and bottom gates, the architecture lays out interacting, 50-nanometer-square, single-electron quantum dots across a chip.
"Our precise modeling elucidates the specific requirements for scalable quantum computing — for the first time we have translated the requirements for fault-tolerant quantum computing into the specific requirements for gate voltage control electronics in quantum dots," said professor Mark Eriksson of the university's Department of Physics.
The group of researchers has concluded that existing silicon fabrication equipment can be used to create quantum computers, albeit at only megahertz speeds today due to the stringent requirements of its pulse generators. To achieve gigahertz operation, the group has pinpointed the device features that need to be enhanced to prevent leakage errors, and has already begun work on fabricating a prototype.
"We believe that quantum computers are possible today with the component technologies we already have in place for silicon," Eriksson said. The team composed their quantum "bits" out of electron spin: up for "1," down for "0." Encoding bits in spins allows a single electron to represent either binary value, and because of the indeterminacy of quantum spins, they can represent both values during calculations to effectively create a parallel process.
Here is an illustration of the process these researchers used.
I saved the best for the end.
With existing fabrication techniques, the team estimates that a million-quantum-dot computer (1,024 x 1,024 array) could be built today and operated in the megahertz range.
The August issue of Scientific American also carries a story about another breakthrough in quantum computing: "Making qubit superpositions in superconductors last longer."
Sources: R. Colin Johnson, EE Times, August 6, 2002; JR Minkel, Scientific American, August 2002 Issue
6:49:23 PM
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