Surface Step (IMAGE) Technische Universität Dresden Caption This is a crystal surface with a step acting as an electron channel, left: scanning tunnel microscopy image, right: scanning tunnel spectroscopy. Credit C. Pauly, RWTH Aachen 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.