Excitons Form Condensate

A new Bose-Einstein condensate formed from excitons rather than from atoms could extend the study of quantum properties. As reported in the Aug. 15 issue of Nature, physicists at the Lawrence Berkeley National Laboratory in Berkeley, Calif., set the stage for condensate formation using laser-excited photoluminescence on quantum wells.

By applying an electrical field perpendicularly to the quantum-well plane, the scientists could bind an electron in one quantum well to a hole in another, forming a relatively stable exciton. Because their mass is smaller than that of atoms, excitons form Bose-Einstein condensates at higher temperatures, in excess of 1 K.