Superconductivity in the land of the "heavy fermions"

An international research team has discovered nonclassical superconductivity at extremely low temperatures in a compound of ytterbium, rhodium, and silicon. The project was a collaboration among physicists of the Technical University of Munich (TUM), the Walther Meissner Institute of the Bavarian Academy of Sciences in Garching, the Max Planck Institute for Chemical Physics of Solids in Dresden, Rice University (Houston, USA), and Renmin University (Beijing, China). Superconductors transport electrical current completely without resistance and are therefore of high interest for technology. While there is a physical explanation for classical superconductivity, it is not yet clear how the phenomenon comes about in high-temperature superconductors. Researchers worldwide are searching for models and examples that could explain it and bring them closer to the long-term goal of achieving room-temperature superconductivity. Now a mechanism by which superconductivity arises at low temperatures in a compound of ytterbium, rhodium, and silicon (YbRh₂Si₂) has been discovered by an international team: Prof. Erwin Schuberth of TUM and the Walther Meissner Institute of the Bavarian Academy of Sciences, Prof. Frank Steglich, director of the Max Planck Institute for Chemical Physics of Solids in Dresden, Prof. Qimiao Si of Rice University, and Prof. Rong Yu of Renmin University. In the land of the "heavy fermions"