Interface Superconductivity in a Dirac Semimetal NiTe(2)

We experimentally investigated charge transport through a single planar junction between a NiTe [Formula: see text] Dirac semimetal and a normal gold lead. At milli-Kelvin temperatures, we observe non-Ohmic [Formula: see text] behavior resembling Andreev reflection at a superconductor–normal metal interface, while NiTe [Formula: see text] bulk remains non-superconducting. The conclusion on superconductivity is also supported by the suppression of the effect by temperature and magnetic field. In analogy with the known results for Cd [Formula: see text] As [Formula: see text] Dirac semimetal, we connect this behavior with interfacial superconductivity due to the flat-band formation at the Au-NiTe [Formula: see text] interface. Since the flat-band and topological surface states are closely connected, the claim on the flat-band-induced superconductivity is also supported by the Josephson current through the topological surface states on the pristine NiTe [Formula: see text] surface. We demonstrate the pronounced Josephson diode effect, which results from the momentum shift of the topological surface states of NiTe [Formula: see text] under an in-plane magnetic field.