Shuntaro Sumita, Kyoto University
Topological Gapless Points in Superconductors: from the viewpoint of symmetry

Topology in quantum physics has attracted much attention in recent condensed matter physics. One famous example is the topological insulator, which has a finite gap in its energy spectrum. On the other hand, topological physics also appears in gapless systems, i.e., topological semimetals. Following this background, we then shed light on superconductors. Some anisotropic superconductors have gapless points in their spectrum, called “superconducting nodes.” Therefore, we ask the question “do nodes meet topology?” In the presentation, I answer this question with “yes” by introducing a classification theory.