Los Alamos theorists correct for quantum weirdness

17 Jun 2002

Scientists are trying to build a computer that uses the bizarre properties of quantum physics to perform calculations many thousands of times faster than today's supercomputers. Now Los Alamos National Laboratory theorists have brought functional quantum computers closer to reality by demonstrating mathematical methods that correct for the ruinous errors that would creep into quantum calculations.

Los Alamos theorist Raymond Laflamme presented his theories "Threshold Accuracy at the quantum computation session of the American Association for the Advancement of Science conference this week.A quantum computer could unravel within seconds the encryption codes that today are unbreakable due to the phenomenal amount of computing power required. However, no one has built a working quantum computer yet, and the first one may be decades away. It is dauntingly difficult to build a machine that manipulates individual atoms to perform many calculations at once by taking advantage of quantum physics. Some scientists argue that quantum computers could never work because quantum states are so fragile there is no way to correct for errors. Error correction strategies used in today's computers are useless for quantum calculations. But if a quantum computer can be built, Laflamme and his Los Alamos colleagues Emanuel Knill and Wojciech Zurek have found error correction strategies that will make the calculations trustworthy.