Optical Chip (image) University of Copenhagen - Niels Bohr Institute Share Print E-Mail Caption The illustration shows an optical chip embedded with a so-called quantum dot. The quantum dot can function as a gateway or transistor for photons. The drawing on top shows that if you send a single photon into the quantum dot, it will be thrown back -- the gateway is closed. The lower drawing shows that if you send two photons, the gateway opens the two photons are sent onwards. So the quantum dot works as a photon contact and this is an important component when you want to build complex quantum photonic circuits on a large scale. Credit Illustration: Alisa Javadi, Niels Bohr Institute, University of Copenhagen Usage Restrictions Illustration: Alisa Javadi, Niels Bohr Institute, University of Copenhagen Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.