Stopped Light Breaks Record
J. Longdell et al.
Phys. Rev. Lett. 95, 063601 (2005)
Light has been stopped in its tracks for more than one second, a thousand times longer than the previous record. Researchers at the Australian National University used a technique called electromagnetically induced transparency, in which a beam of laser light puts the atoms in a solid sample into a state in which a signal light pulse can be trapped. Most previous stopped-light demonstrations have used atomic gases, rather than solid-state materials. Light had previously been stopped in a solid (yttrium-silicate doped with atoms of praseodymium), but only for a few milliseconds. Although the efficiency of the storage was low in this experiment, the researchers believe they can improve the efficiency by using a thicker sample and by increasing the concentration of praseodymium in the sample. The technique could be useful in quantum information processing applications.
Discovering Diversity in Darwinian Evolution
G. Meszena et al.
Physical Review Letters (upcoming article)
A new model clarifying the mathematical basis for diversity in Darwinian evolution has been developed by a collaboration of Hungarian, Finnish, Dutch, and Austrian researchers. One of the questions posed by evolutionary theories regards how slight changes in species can be reconciled with the "survival of the fittest" rule. After all, if slightly different species exist simultaneously, a nave model suggests that the most fit would immediately wipe out the lesser fit species. The new model, however, confirms that related species emerging from a common ancestor quickly evolve in diffe
Contact: James Riordon
American Physical Society