In an effort lead by Leonid Butov, physics professor at UC-San Diego; "Physicists at UC San Diego 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."
Read more for a cogent explanation on the importance of coherence with graphic.
Isn't it exciton! Like a spontaneous pearl necklace! (go ZZ-Top!)