Multi-band character revealed from Weak-antilocalization effect in Platinum thin films

Abstract

Platinum (Pt) has been very much used for spin-charge conversion in spintronics research due to it's large intrinsic spin-orbit interaction. Magnetoconductance originated from weak-antilocalization effect in quantum interference regime is used as a powerful tool to obtain the microscopic information of spin-orbit interaction and coherence phase breaking scattering process among itinerant electrons. To acquire the knowledge of different types of scattering processes, we have performed magnetoconductance study on Pt thin films which manifests multi-band (multi-channel) conduction. An extensive analysis of quantum interference originated weak-antilocalization effect reveals the existence of strong (weak) inter-band scattering between two similar (different) orbitals. Coherence phase breaking lengths ($l_{\phi}$) and their temperature dependence are found to be significantly different for these two conducting bands. The observed effects are consistent with theoretical predication that there exist three Fermi-sheets with one $s$ and two $d$ orbital character. This study provides the evidence of two independent non-similar conducting channels and presence of anisotropic spin-orbit interaction along with $e$-$e$ correlation in Pt thin films.