All the materials humans work with are made up of atoms. The interaction of atoms and their arrangement determine the properties of a material. Most of the researchers in the field of matter and materials at PSI want to find out more about how the internal structure of different materials relates to their observable properties. Fundamental research in this area contributes to the development of new materials with a wide range of applications, for example in electrical engineering, medicine, telecommunications, mobility, new energy storage systems, quantum computers and spintronics. The phenomena investigated include superconductivity, ferro- and antiferromagnetism, spin fluids and topological insulators.