Making quantum computers reliable

CALCULATING machines that run on quantum bits (known as qubits, for short) are, by some accounts, the future of computation. Quantum computers have the theoretical advantage that they can solve with ease certain mathematical problems, such as the factorisation of large numbers, which are hard or impossible for classical machines. This is possible thanks to a qubit’s ability to remain, through the peculiarities of quantum mechanics, in many quantum states simultaneously. The more qubits a computer has, the more mind-bogglingly gigantic are the calculations it can handle. Finance, medicine, chemistry and artificial intelligence are thus all expected to be transformed by quantum computing. And where the future is, there surely will Google be also. The firm sets great store by its quantum-computing project, which it calls Project Bristlecone. This is intended to develop a “quantum-supremacy device”, ie, one that is palpably and provably faster than a traditional computer of equivalent... Continue reading