New class of Chiral topological nodes in transition metal silicide CoSi

Exotic chiral topological nodes with nonzero chern number and multiple degeneracy, distinct from conventional Dirac and Weyl nodes, could exist in crystalline semimetals with certain space group symmetries. The projections of these chiral topological nodes with opposite chern number are connected by topologically protected surface fermi arcs. Several other types of chiral topological nodes have been predicted by theorists, but the direct experiment evident is still lacked. Here, we will report that two types of new chiral nodes are revealed by using angel-resolved photoemission spectroscopy in transition metal silicide CoSi.