Nanowire conductance experiments above and below the reservoirs Curie temperature

The transport properties of Ni nanowires are studied using a Scanning Tunne ling Microscope (STM) under clean high vacuum conditions. A basically flat nanowire conductance histogram is found independently of the magnetic stare of the electrodes. This agrees with our previous studies in air but disagr ees with recently published results. The possible origin of these discrepan cies, together with additional experiments trying to discern the existence of a spin-dependent conductance in ferromagnetic nanowires, are presented.