Nobel Prize in Physics 2012
Once again the Nobel Prize in Physics has been awarded for work in optics. ICO congratulates the 2012 Nobel Awardees in Physics: Serge Haroche Collège de France and École Normale Supérieure, Paris, France, and David J. Wineland , National Institute of Standards and Technology and University of Colorado, Boulder, Colorado, USA. The Swedish Academy awarded them the Nobel Prize "for ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems".
|Serge Haroche, a surveyor of the quantum world , won the Gold Medal of the CNRS in 2009. In February 2012 he delivered a lecture at Harvard University entitled “Juggling with photons in a box to explore the quantum world”, in which he presented an overview of his team’s work.|
Haroche determined how, by means of cavity quantum electrodynamics, to detect a photon without absorbing it. In a cavity consisting of two highly reflecting mirrors, a photon is reflected back and forth billions of times and remains some tenth of a second in the cavity, long enough for the photon to be detected without its being destroyed. The photon detector is a Rydberg atom, an atom in a highly excited state, which is very sensitive to interaction with radiation. It is possible to create within the cavity specific quantum states of light for quantum information experiments, like the Schrodinger cat state, and to use the Rydberg atoms to perform the radiography of those quantum states of light.
|David J. Wineland delivered the Quantum Frontiers Distinguished Lecture on Atomic Clocks and Ion Trap Quantum Computing at the University of Waterloo in January 2012. More than 20 years ago he succeeded in trapping a mercury ion by means of a combination of oscillating and static electric fields.|
Ion traps prevent ion loss, heating caused by collisions and blackbody radiation, and his group has been able to maintain an ion trapped for periods as long as six months. In more recent work Wineland and his group were able to create and detect entangled states of two and four trapped ions without destroying them.
Wineland noted that ion trapping could be used for quantum computation, for manipulating individual qubits and putting them in a superposition state with quantum coherence lasting for half an hour. For a two-qubit gate, his group has achieved a record 0.5% operation error.
With their work they have demonstrated the possibility of detecting and manipulating entangled states, a fundamental achievement on the path to quantum computing. Although Wineland acknowledges that large-scale quantum computing is still “way out in the distance,” it is expected that it will ultimately produce computing machines able to tackle problems that we only dream of solving now.