Noncollinear Spin Torque Effect in Magnetic Heterojunctions: Combined First-Principles Calculation and TB-NEGF Method*

In this study, our newly developed “JunPy” [1] package has successfully combined the self-consistent Hamiltonian by using the first-principles calculation [2], including multi-band dispersion relation and complicated interfacial coupling, with the TB model and the non-equilibrium Green’s function (NEGF) method to investigate the noncollinear magnetotransport properties in nm-scale magnetic heterojunctions. This program is first testified by the spin-polarized currents and the noncollinear spin torque effect in conventional Fe/MgO/Fe MTJ. We further employed it to predictthe giant field-like spin torque (FLST) effect in the amine-ended single-molecule magnetic junction [3], which may open a new avenue formultifunctional manipulation in next-generation organicFLST-MRAMs with lower power consumption.

[1] JunPy package: https://labstt.phy.ncu.edu.tw/junpy
[2] Nanodcal package: http://nanoacademic.ca/showArticle.jsp?id=17
[3] Y. –H. Tang and B. –H. Huang, J. Phys. Chem. C 122, 20500 (2018).