[17a-D61-1~10] 10.3 Spin devices, magnetic memories and storages

9:15 AM - 9:30 AM JST(12:15 AM - 12:30 AM UTC)English Presentation

[17a-D61-2] Theoretical approach for the TMR oscillation as a function of the barrier thickness

〇Keisuke Masuda¹, Thomas Scheike¹, Hiroaki Sukegawa¹, Yusuke Kozuka¹, Seiji Mitani¹, Yoshio Miura^1,2 (1.NIMS, 2.KIT)

Keywords:

TMR,MTJ

Oscillation of the TMR ratio as a function of the insulating barrier thickness called the “TMR oscillation” was firstly observed by Yuasa et al. in an Fe/MgO/Fe(001) MTJ with a high TMR ratio. However, the underlying mechanism of this phenomenon has yet to be clarified. In this work, we propose a possible mechanism of the TMR oscillation. Our idea is to consider the superposition of wave functions with opposite spins and different Fermi momenta for the tunneling problem. We find that the calculated conductances and TMR ratio oscillate with a period of ~ 3 Angstrom by varying the insulating barrier thickness, consistent with experimental observations.