Frenchman Serge Haroche (pictured, right) and American David Wineland (bottom left), both 68, have shared the 2012 Nobel prize in physics, for their work on “ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems”.
Announcing the award this morning in Stockholm, the Nobel Committee said: “Through their ingenious laboratory methods Haroche and Wineland together with their research groups have managed to measure and control very fragile quantum states, which were previously thought inaccessible for direct observation.”
An individual ion or photon behaves according to the rules of quantum mechanics, with phenomena such as superposition (when particles can exist in several states at the same time) and entanglement (in which separate particles share a link across space). But observing these strange behaviours is a delicate experiment, because they are lost when an individual particle interacts with many others.
Wineland, who works at the National Institute of Standards and Technology and the University of Colorado in Boulder, uses electric fields to trap individual ions and laser beams to probe their behaviour. This has allowed him to build precise optical clocks and take steps towards building quantum computers, in which ‘bits’ instead become quantum-entangled ‘qubits’, which could perform many calculations in parallel.
Haroche, at the Collège de France and Ecole Normale Supérieure in Paris, traps microwave photons in a cavity, using beams of atoms to detect them. He has followed how a photon’s quantum state changes, step by step, over time.
Nature‘s full story follows later (UPDATE – it’s here).