Magnetically stable zero-bias anomaly in Andreev contact to the magnetic Weyl semimetal Co${}_3$Sn${}_2$S${}_2$

Abstract

Being encouraged by the interplay between topology, superconductivity and magnetism, we experimentally investigate charge transport through the interface between the Nb superconductor and the time-reversal symmetry breaking Weyl semimetal Co${}_3$Sn${}_2$S${}_2$. In addition to the proximity induced superconducting gap, we observe several subgap features, among which the most interesting is the prominent subgap zero-bias anomaly, absolutely stable against external magnetic fields up to the critical field of Nb. As the promising scenario for the zero-bias anomaly to appear in transport characteristics, we consider the proximity induced zero-energy Andreev bound states interfaced with the half-metallic Co${}_3$Sn${}_2$S${}_2$ and influenced by the strong spin-orbit coupling and large Zeeman splitting.