Spin-resolved electron transport through magnetic nanostructures studied by a low-temperature multiprobe-STM
Final Report Abstract
We have succeeded in setting up a spin-polarized four-probe STM system in UHV and in detecting magnetic contrast on Fe double-layer nanowires as well as 3D Fe islands on W(110) substrates using the spin-polarized four-probe STM. However, the S/N-ratio is only about ~1 so far, which needs to be improved for future investigations with spin resolution. Transport properties of graphite flakes and monolayer graphene have been studied. A microscopic folding part of graphite has been accessed by a precisely-positioned mobile probe. It has been found that the folding part shows a higher resistance than a flat area. It has been demonstrated that the folding part and its resistance can be manipulated by the lateral motion of a probe tip. These unique characteristics of our four-probe STM have also been applied to graphene on SiO2and SiC substrates. In the future, we intend to apply our spin-polarized four-probe STM system to local spin-resolved transport studies of specially prepared graphene samples and their edges, as well as to the new class of topological insulators.
