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Toffoli

Lauren Schenkman for Inside Science News Service reports that physicists Lev Levitin and Tommaso Toffoli at Boston University have declared a speed limit on computing, no matter how small components get.

Levitan

In the early 1980s, Levitin singled out a quantum elementary operation, the most basic task a quantum computer could carry out. In a paper published today in the journal Physical Review Letters, Levitin and Toffoli present an equation for the minimum sliver of time it takes for this elementary operation to occur. This establishes the speed limit for all possible computers.

“From a theorist’s perspective, it’s good to know that fundamental limits are there, sort of an absolute ceiling. You may say it’s disappointing that we can’t build infinitely fast computers, but as a picture of the world, if you have a theory of physics allows for infinitely fast computation, there could be a problem with that theory.” – Scott Aaronson, an assistant professor of electrical engineering and computer science at the Massachusetts Institute of Technology