UC San Diego Physicists Find Patterns in New State of Matter

Physicists at the University of California, San Diego have discovered patterns which underlie the properties of a new state of matter. the scientists describe the emergence of "spontaneous coherence," "spin textures" and "phase singularities" when excitons-the bound pairs of electrons and holes that determine the optical properties of semiconductors and enable them to function as novel optoelectronic devices-are cooled to near absolute zero. This cooling leads to the spontaneous production of a new coherent state of matter which the physicists were finally able to measure in great detail in their basement laboratory at UC San Diego at a temperature of only one-tenth of a degree above absolute zero. The discovery of the phenomena that underlie the formation of spontaneous coherence of excitons is certain to produce a better scientific understanding of this new state of matter. It will also add new insights into the quirky quantum properties of matter and, in time, lead to the development of novel computing devices and other commercial applications in the field of optoelectronics where understanding of basic properties of light and matter is needed. The physicists discovered a correlation between the coherence (at left) and spin polarization (at right) of the excitons. The research team was headed by Leonid Butov, a professor of physics at UC San Diego who in 2002 discovered that excitons, when made sufficiently cold, tend to self-organize into an ordered array of microscopic droplets, like a miniature pearl necklace.