Scientists have for the first time observed the spontaneous production of coherence. Modern physics was born by the discovery that all particles in nature are also waves. Coherence means that such waves are all 'in sync.' The spontaneous coherence of the matter waves is the reason behind some of the most exciting phenomena in nature.

A team of four physicists at UCSD working in collaboration with a materials scientist at UC Santa Barbara have for the first time observed the spontaneous production of coherence within "excitons," the bound pairs of electrons and holes that enable semiconductors to function as novel electronic devices. The effort was headed by Leonid Butov, a professor of physics at UCSD who in 2002 led a similar team at the Lawrence Berkeley National Laboratory to the discovery that excitons, when made sufficiently cold, tend to self-organize into an ordered array of microscopic droplets, like a miniature pearl necklace.

"What is coherence and why is it so important?" said Butov. "To start with, modern physics was born by the discovery that all particles in nature are also waves. Coherence means that such waves are all 'in sync.' The spontaneous coherence of the matter waves is the reason behind some of the most exciting phenomena in nature such as superconductivity and lasing."

"A simple way to visualize coherence is to imagine cheering spectators at a stadium making 'a wave'," added Michael Fogler, an assistant professor of physics at UCSD and a co-author of the paper. "If the top rows get up and down at the same time as the bottom ones, the rows are mutually coherent. In turn, coherence is spontaneous when the cheering is done on the spectator's own initiative and is not orchestrated by the directions of an external announcer."

A famous example of spontaneous coherence of matter waves is the Bose-Einstein condensate, which is a state predicted by Einstein some 80 years ago. The Bose-Einstein condensate is a gas of atoms so dense and cold that their matter waves lose their individuality and condense into a "macroscopic coherent superatom wave.">from *UC San Diego Physicists Observe New Property of Matter*. November 1, 2006

related context
> bose-einstein_condensate.
> direct proof of dark matter. september 1, 2006
> two super heavy elements discovery ratified. february 10, 2006
> disorder-induced synchronization. april 14, 2006
> synchrony: order is inevitable. april 9, 2003
> the bose-einstein condensate. october 11, 2001

imago
> stick together ... my best friends

sonic flow
> spontaneous production of
coherence [stream]
spontaneous production of
coherence [download]