Abstract

Recently, a very unusual excitonic-transport regime has been discovered in Cu₂O.¹ At sufficiently high particle densities and low temperatures, optically inactive paraexdtons initially created randomly near the front surface of a single crystal were observed to propagate ballistically through the sample in the form of a packet of limited size over unusually large distantes, appreaching 1 cm. This anomalous propagation has been attributed to excitonic superfluidity, a drag-free motion itself closely associated with Bose-Einstein condensation of excitons.¹

© 1994 Optical Society of America