Error-Correcting Code Keeps Quantum Computers on Track
Barry A. Cipra · Science · 1996
Quantum computers, which could exploit systems such as the energy states of a row of atoms to perform vast numbers of computations at the same time, have remained in the realm of fantasy. A major barrier has been the fragility of quantum states, which makes quantum systems vulnerable to errors. Classical error-correction schemes won't work in a quantum computer, because they rely on duplicate bits, and in quantum systems information vanishes when you read and copy it. A new mathematical scheme, however, makes it possible—at least in theory—to nudge a quantum system back into line without directly looking at it. Computers/Math