Three-dimensional (3D) topological semimetals represent a new class of topological
matters. The study of this family of materials has been at the frontiers of condensed matter
physics, and many breakthroughs have been made. Several topological semimetal phases,
including Dirac semimetals (DSMs), Weyl semimetals (WSMs), nodal-line semimetals
(NLSMs), and triple-point semimetals, have been theoretically predicted and experimentally
demonstrated. The low-energy excitation around the Dirac/Weyl nodal points, nodal line, or�…