The 2012 Nobel Prize in Physics was awarded jointly to Serge Haroche and David J. Wineland for experimental methods that enable measuring and manipulation of individual quantum systems.

Wineland co-authored an August, 2008, Scientific American article explaining his work, titled Quantum Computing with Ions.

Philip Yam wrote a review article that includes coverage of this material in the June, 1997, Scientific American, titled Bringing Schrödinger's Cat to Life, available here text-only and in full in our digital archive.
 

The official Nobel Prize press release reads:

The 2012 Nobel Prize in Physics was awarded jointly to Serge Haroche and David J. Wineland "for ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems".

Particle control in a quantum world

Serge Haroche and David J. Wineland have independently invented and developed methods for measuring and manipulating individual particles while preserving their quantum-mechanical nature, in ways that were previously thought unattainable.

The Nobel Laureates have opened the door to a new era of experimentation with quantum physics by demonstrating the direct observation of individual quantum particles without destroying them. For single particles of light or matter the laws of classical physics cease to apply and quantum physics takes over. But single particles are not easily isolated from their surrounding environment and they lose their mysterious quantum properties as soon as they interact with the outside world. Thus many seemingly bizarre phenomena predicted by quantum physics could not be directly observed, and researchers could only carry out thought experiments that might in principle manifest these bizarre phenomena.

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. The new methods allow them to examine, control and count the particles.

Their methods have many things in common. David Wineland traps electrically charged atoms, or ions, controlling and measuring them with light, or photons.

Serge Haroche takes the opposite approach: he controls and measures trapped photons, or particles of light, by sending atoms through a trap.

Both Laureates work in the field of quantum optics studying the fundamental interaction between light and matter, a field which has seen considerable progress since the mid-1980s. Their ground-breaking methods have enabled this field of research to take the very first steps towards building a new type of super fast computer based on quantum physics. Perhaps the quantum computer will change our everyday lives in this century in the same radical way as the classical computer did in the last century. The research has also led to the construction of extremely precise clocks that could become the future basis for a new standard of time, with more than hundred-fold greater precision than present-day caesium clocks.

The transcript of the podcast reads:

“This year’s Nobel Prize in physics is about the interaction between light and matter.”
Physics Nobel committee member Lars Bergstrom made the announcement just after 5:45am Eastern time.

“The Royal Swedish Academy of Sciences has decided to award the 2012 Nobel Prize in physics to Serge Haroche, at Collège de France and Ecole Normale Supérieure, Paris, France, and David J. Wineland, at National Institute of Standards and Technology (NIST) and University of Colorado Boulder, USA. And the Academy citation runs, ’for ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems’”.

The work has enabled the entire field to experimentally examine quantum states, the weird behavior of matter on subatomic scales, that were formerly only open to analysis theoretically. The most obvious applications of the measurement and manipulation of quantum systems are atomic clocks of unprecedented accuracy and the eventual advent of quantum computers.

Just after the announcement, Physics Nobel committee member Per Delsing explained to a reporter that this work enables researchers “to take one of the very first steps to show that you can do quantum operations on a quantum system, that’s the first step toward a quantum computer.”
Reporter: “What would a quantum computer do that computers cannot?”
Delsing: “So there are certain algorithms that a quantum computer can do much much faster than an ordinary computer, and the prime example is to factor large numbers into primes, that would be extremely much faster with a quantum computer. The future will tell, I’m sure there will be also a number of other things that will be useful on a quantum computer.”
Reporter: “So why don’t we have it here now?”
Delsing: “Because this is very hard to do. Today we have awarded a Nobel to these two guys who have taken the first steps to have control on a single system, but to make a quantum computer you would have to have the same amount of control on very many particles at the same time.”
Reporter: “So it will not come next year as a Nobel Prize.”
Delsing: “I can almost promise that.”