The 65h JSAP Spring Meeting, 2018

Presentation information

Oral presentation

10 Spintronics and Magnetics » 10.2 Fundamental and exploratory device technologies for spin

[17p-D104-1~10] 10.2 Fundamental and exploratory device technologies for spin

10.1と10.2と10.3のコードシェアセッションあり

Sat. Mar 17, 2018 1:00 PM - 3:30 PM D104 (56-104)

Takahiro Moriyama(Kyoto Univ.)

2:00 PM - 2:15 PM

[17p-D104-5] Edelstein Magnetoresistance Governed by Interface-bulk Contributions

Junyeon Kim1, Yan-Ting Chen1, Shutaro Karube1,2, Saburo Takahashi3, Kouta Kondou1, Gen Tatara1, YoshiChika Otani1,2 (1.RIKEN-CEMS, 2.ISSP, Univ. of Tokyo, 3.IMR, Tohoku Univ.)

Keywords:Rashba interface, Edelstein effect, Magnetoresistance

There is a puzzling issue on the conversion efficiency although many interests on the spin/charge current interconversion at the two-dimensional (2D) interfaces. Contrast to the bulk spin Hall materials, the conversion efficiency at the 2D interfaces shows order of magnitude difference between the charge-to-spin current conversion and the spin-to-charge current conversion. Here we provide a practical solution on this issue through an experimental study on the spin transport and a theoretical study considering a spin relaxation process nearby the interface [1].
Since then a report by Nakayama et al., we have perceived that the spin/charge current interconversion by the spin-orbit interaction leads a modulation of the resistance [2]. We call Edelstein magnetoresistance (Edelstein MR) for such resistance modulation by the Edelstein effect at the Rashba or other 2D interfaces. In this study, we observed the Edelstein MR in CoFe/Cu/Bi2O3 thin films, where the Cu/Bi2O3 interface shows the Rashba splitting. We also developed a general analytical model considering with the spin relaxation process. As shown in Fig. 1(a), the accumulated spins at the interface by the Edelstein effect will leave outside the interface, or be relaxed inside the interface [1,3]. Based on the model, we analyzed the Cu thickness dependence of the Edelstein MR (Fig. 1(b)). Interestingly, this study reveals only 34 % of the accumulated spins can get out the interface [1].