To measure a single quantum dot, the scientists positioned the objective over a single bright spot, roughly 300 nm in diameter. They found that a dead time exists between the photon emissions from a dot, corresponding to the time it takes for its energy level to rise again to the excited state. What surprised everyone was that the phenomenon occurred in an uncooled setup. The ability of quantum dots to be either on or off corresponds directly to the binary system of ones and zeros used in everyday computers. Proving that a binary system exists in room-temperature quantum dots is a fundamental step toward their practical use in computing.
More research is required, however.
Atac Imamoglu, a professor of physics and of computer and electrical engineering at the university and principal investigator in the study, said that how quickly the dots turn on and off remains unknown. The group also hopes to develop quantum cryptographic systems based on such sources. Laurin Publishing Co. Inc. All rights reserved. Reproduction in whole or in part without permission is prohibited.