Interplay between topological surface states and superconductivity in SmB6/NbN tunnel junctions

We report the interplay between Cooper pairs in superconductor NbN and topological surface states in $\mathrm{Sm}{\mathrm{B}}₆$ nanowire through magnetotransport measurements. The NbN electrodes are superconductive below 13.5 K and the $\mathrm{Sm}{\mathrm{B}}₆$ nanowire shows the surface states dominate transport below 6 K. The tunneling between the topological surface states in $\mathrm{Sm}{\mathrm{B}}₆$ and the Cooper pairs in NbN gives rise to a transition from positive to negative magnetoresistance between 0 and 14 T.