Klein Tunneling (image) University of Maryland Share Print E-Mail Caption In Klein tunneling, a negatively charged electron (brightly colored sphere) can transit perfectly through a barrier. In a new experiment, researchers observed the Klein tunneling of electrons into a special kind of superconductor. As electrons tunneled through the barrier, they each picked up a partner, doubling the conductance measured in the experiment. To balance out the extra negatively charged electron, a positively charged hole (dark sphere) is reflected back from the barrier--a process known as Andreev reflection. Credit Emily Edwards/Joint Quantum Institute Usage Restrictions None 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.