links for 2009-01-02

"I wake up to the sun's early morning glow or from the Luganda streaming through my mosquito net, which I'm not sure. It is another day in Uganda, a handful of kilometers beneath the equator. I can easily recall the first days in Africa when the sun did not wrestle me out of bed at dawn and when the Luganda was strange and invoked loneliness. But now, 5 months in, I slip out of bed and into the day easily. "

"The 2009 Edge World Question is What game-changing scientific ideas and developments do you expect to live to see?. It seems like a lot of people ignored the question, but most were still an interesting read. As per previous years, here are a few of my favourites."

"We have observed multiphoton assisted recombination in the presence of a 38.8 GHz microwave field. Stimulated emission of up to ten microwave photons results in energy transfer from continuum electrons, enabling recombination. The maximum electron energy loss is far greater than the 2Up predicted by the standard "simpleman's" model."

A fundamental limit to the sensitivity of optical interferometry is thermal noise that drives fluctuations in the positions of the surfaces of the interferometer's mirrors, and thereby in the phase of the intracavity field. Schemes for reducing this thermally driven phase noise are presented that rely upon the coherent character of the underlying displacements and strains.

"We report the observation of entanglement between a single trapped atom and a single photon at remote locations. The degree of coherence of the entangled atom-photon pair is verified via appropriate local correlation measurements, after communicating the photon via an optical fiber link of 300 m length to a receiver 3.5 m apart."

"We experimentally investigate the role of localization on the adiabaticity of loading a Bose-Einstein condensate into a one-dimensional optical potential comprised of a shallow primary lattice plus one or two perturbing lattice(s) of incommensurate period. We find that even a very weak perturbation causes dramatic changes in the momentum distribution and makes adiabatic loading of the combined lattice much more difficult than for a single period lattice. "

"We propose an experiment to directly prove the commutation relation between bosonic annihilation and creation operators, based on the recent experimental success in single-photon subtraction and addition. We devise a single-photon interferometer to realize coherent superpositions of two sequences of photon addition and subtraction. Depending on the interference outcome, the commutation relation is directly proven or a highly nonclassical state is produced."