Spin Cross-Correlation Experiments I (IMAGE) University of Basel Caption Electrons leave a (conventional) superconductor (S) only as pairs and only with opposite spins (arrow up or down, red or blue). If both electron paths are blocked for the same type of spin by parallel spin filters (here for spin down (blue)), a single electron with spin up (red) could in principle exit, but paired electrons from the superconductor are blocked, which ideally suppresses both electrical currents. Credit Department of Physics, University of Basel, Scixel Usage Restrictions Credit must be given to the creator. Adaptations must be shared under the same terms. License CC BY-SA 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.