(IMAGE) Physikalisch-Technische Bundesanstalt (PTB) Caption This image shows an etched semiconducting channel with electron source (A) and barrier (B). The electron pairs are emitted by the source and split at the barrier into two separate electric conductors (arrow). Credit (Fig.: PTB) Usage Restrictions None License Licensed content 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.