Spin-polarized scanning tunneling microscopy with quantitative insights into magnetic probes

Tunneling in spin-polarized scanning tunneling microscopy. a A schematic illustration of the tunneling current between a magnetic sample and a magnetic tip in scanning tunneling microscopy (STM) in an external magnetic field μ0 H. b, c A simplified picture of spin-polarized tunneling within a hypothetical spin-split density of states model in parallel (P) and antiparallel (AP) magnetization orientations. The spin orientation of the tunneling electrons is assumed to be conserved during tunneling, i.e., spin-up electrons always tunnel into spin-up states and spin-down electrons always tunnel into spin-down states. Arrows (bottom) indicate the DOS of spin-up and spin-down electrons. The spin direction is antiparallel to the magnetic moment [64]. M T and M S (top arrows) denote the magnetization orientation of tip and sample, respectively. b P and c AP alignment of tip and sample magnetizatio