Strong-Coupling Anisotropic S-Wave Superconductivity In The Type-Ii Weyl Semimetal Tairte4

TaIrTe4 is a recently discovered type-II Weyl semimetal, hosting only four Weyl points. Here, we study the cleaved TaIrTe4 crystal using scanning tunneling microscopy/spectroscopy and find that it also hosts a superconducting state with a transition temperature of 3.9 K. From Dynes function fitting, the superconducting phase is consistent with anisotropic s-wave pairing, with a superconducting gap of 1.31 meV. This value leads to a value of 2 Delta(max)/k(B)T(C) = 7.81, much larger than the 3.53 predicted by Bardeen-Cooper-Schrieffer theory for weak-coupling superconductors. The critical field is found to be 0.7 T based on the analysis of tunneling conductance as a function of magnetic field. Two types of nonmagnetic defects on the TaIrTe4 surface are observed, neither of which induce bound states inside the superconducting gap, further supporting conventional s-wave superconductivity in the TaIrTe4 system.