Evaluation of temperature-dependent spin Hall angle in CoFeB/MgO/Pt tunneling junctions by using Spin Hall effect tunneling spectroscopy

摘要

Spin Hall effect (SHE) and its inverse effect (i-SHE) are promising ways to generate and to detect spin currents, respectively. The spin Hall angle θsh is the conversion efficiency between charge current and spin current. Various methods to evaluate θsh have been demonstrated, such as spin pumping [1], harmonic measurement [2] and lateral spin valve [3]. Recently, SHE tunneling spectroscopy (SHT) [4] has been proposed as an alternative way to evaluate θsh. In this method, i-SHE signal is obtained via tunneling spin polarized currents, which is applicable for not only metals but also topological insulators [5]. In this study, we explore the detailed spin dependent transport mechanism in spin Hall effect tunneling devices.