Superconductivity and quantum oscillations in single crystals of the compensated semimetal CaSb2

Identifying new bulk superconductors with topologically nontrivial bands in the normal state is critical for achieving topological superconductivity with Majorana fermions for applications in quantum computing. Here, the authors perform measurements on the nodal-line semimetal CaSb${}₂$ using single crystals for the first time, which reveal superconductivity and electron-hole compensation. The Sb atoms form a distorted square net in the crystal structure and contribute strongly to the electron bands at the Fermi level, and connections may be drawn to the well-known square net semimetals. The meeting of superconductivity and topology here should open up the diantimonides as a platform for realizing topological superconductivity.