[8p-E207-1~17] 10.4 Spintronics in semiconductor, topological material, superconductor, and multiferroics

3:30 PM - 3:45 PM JST(6:30 AM - 6:45 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation AwardEnglish Presentation

[8p-E207-8] Analysis of the relationship between spin polarization and resistance–area product in CoFe/Fe/Mg/SiN/n+-Si tunnel junctions

〇Ryosuke Shimizu¹, Shoichi Sato^1,2, Masaaki Tanaka^1,2,3, Ryosho Nakane^1,3,4 (1.EEIS, 2.CSRN, 3.NanoQuine, 4.d.lab)

Keywords:

spintronics,spin injection,Si

In previous MgO/MAO studies, high P_S was obtained at high RA, but P_S monotonically drops as RA is reduced and reaches half its maximum at RA = 6.0 kΩ·μm². To explain this behavior, we proposed the two-path model, in which the tunneling current consists of two paths: path A with high spin polarization and a long decay length, and path B with low spin polarization and a short decay length. Since path A dominates at high RA, its spin polarization P_S,A gives the upper limit of P_S. The decrease in P_S at low RA is attributed to the increasing contribution of path B. In our SiN junctions, we obtained higher P_S than the MgO system at comparable low RA; however, it is unclear whether this originates from an increase in P_S,A or a smaller fraction of path B. By analyzing the P_S–RA plot, these two possibilities can be distinguished. The fitting result shows that P_S,A is higher, while the fraction of path B has not changed.