Fermi Surface Around Cobalt Atom (IMAGE) Helmholtz Association Caption This is the Fermi surface of copper metal. The colors represent the curvature of the surface, which determines the propagation properties for electron waves. Credit Forschungszentrum Jülich and Martin Luther University Halle, Germany Usage Restrictions Please provide credit information. 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.