Kumar Sourav Das, University of Groningen (IMAGE) University of Groningen Caption This is Dr. Kumar Sourav Das, first author of the study in Nano Letters. Credit K.S. Das 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.