Fig. 2
From: Probing hybrid metallic sandwiches with nonlocal four-terminal electrical measurements
Effect of the difference between near-surface Rs and bulk Rb resistances. (a) Calculated four-probe resistance RAB, CD versus the ratio Rs/Rb where \({R_{{\text{AB}}}}={R_{{\text{CD}}}}={R_{{\text{AD}}}}={R_{{\text{CB}}}}={R_{\text{b}}}\) and \({R_{{\text{AC}}}}={R_{{\text{DB}}}}={R_{\text{s}}}\). The red lines in the insets indicate the dominant directions of charge flows at the surface (\({R_{\text{s}}}<{R_{\text{b}}}\)) and in the bulk (\({R_{\text{s}}}>{R_{\text{b}}}\)). (b) Measured temperature dependence of CPP four-probe resistances RAB, CD(T) for NbN(80 nm)/F(50 nm)/NbN(80 nm) trilayers with F = Co, Ni, and NiCu (dashed-dotted, dotted, and dashed lines, respectively) compared with the same characteristic for a single NbN (160 nm) layer (solid line).
