Physicists Find Patterns in New State of Matter Called Spontaneous Coherence in Excitons

Posted on March 29, 2012

UC San Diego physicists have produced the most detailed images ever seen of a new property of matter called spontaneous coherence in excitons (bound pairs of electrons and holes). The physicists cooled samples of gallium arsenide to near absolute zero and then hit them with laser light to produce particles called excitons. Light from the excitons was sent through a complex set of mirrors called an interferometer, which divides the light into two different paths.

Spontaneous Coherence Exciton Beads


The researchers found that excitons self organize into an ordered array of microscopic beads when cooled to near absolute zero. This array of beads looks like a miniature pearl necklace. Within this condensate, the physicists found spin textures and phase singularities that are characteristic of this new state of matter.

Spontaneous Coherence Spin Polarization


Take a look:



Alex High, a UC San Diego graduate student and the first author of the paper, says, "It was a surprise to see this pattern. And it was even more surprising that polarization measurements showed that there was a strong correlation between the coherence and polarization."

The research paper was published here in the March 29 issue of the journal Nature.

Photos: UC San Diego