Quantum computers
Quantum computing kit With basic information processing units (qubits) governed by the exotic phenomena of quantum mechanics, quantum computers have the potential to be far better at performing certain calculations than today's computers using conventional 'bits'. That said, it's far from clear what technology practical quantum computers — if and when they arrive — will use. In an extensive review, six researchers from major labs in the field describe the latest work on the hardware for quantum information systems. Current materials are compared — including the nuclear spins of donor atoms in doped silicon, electron spins in gallium arsenide and nitrogen-vacancy centres in diamond — and the materials that are yet to come are speculated upon.