2D superconductivity in a nodal loop semimetal with purely 3D Fermi surfaces

The exotic properties of topological semimetals (TSMs) have attracted great attention and significant efforts have been made in exploring new topological phases and materials. Some of the TSMs are predicated to host exotic band properties, such as butterflylike coplanar ellipses nodal lines. Here in such a TSM, our transport experiments reveal a 2D superconductivity. This is very surprising given that our quantum oscillations experiments show 3D Fermi surface. We discuss the possible origin of the superconductivity in light of our angle-resolved photoemission spectroscopy and first-principles calculation results.