講演情報
[15p-K303-1]BiSb トポロジカル絶縁体と磁性界面におけるスピン軌道トルクを最適化するための金属、酸化物、および金属酸化物ハイブリッド中間層の研究
〇(D)張 瑞顕1、ラー クォング2、リュー ジャウヨング2、シュウ レーイー2、ヨーク ブライアン・アー1、フワング チャーンギイ1、ラー ソン2、前田 麻貴3、脱 凡3、高野 公史3、劉 敏1、南波 彰太1、ファム ナムハイ1 (1.東科大、2.WD（米）、3.WD（日）)
キーワード：
トポロジカル絶縁体、界面効果、スピンホール効果
In this work, we have investigated and compared the effects of inserting metal, oxide, and hybrid metal-oxide interlayers such as NiFeGe, MgO, NiFeGe/MgO, and NiFeGe/MgTiO, respectively, in between the 10 nm BiSb layer and ferromagnetic (FM) [0.8 nm Co40Fe60] layer that was deposited at room temperature on a silicon oxide substrate.
Both NiFeGe and MgO improve Spin Hall angle (SHA) of BiSb comparing with that of BiSb with no interlayer. Since both NiFeGe and MgO can prevent unwanted interaction between the FM and TI, they can protect the BiSb topological surface states and result in improved intrinsic SHA. Meanwhile, the hybrid NiFeGe (9 Å)/ MgO (3 Å) interlayers shows the highest SHA.
Our study provides a useful framework for understanding ultrahigh charge-to-spin conversion efficiencyand guidance on increasing it by optimizing the interlayer material for ultralow power SOT applications.
Both NiFeGe and MgO improve Spin Hall angle (SHA) of BiSb comparing with that of BiSb with no interlayer. Since both NiFeGe and MgO can prevent unwanted interaction between the FM and TI, they can protect the BiSb topological surface states and result in improved intrinsic SHA. Meanwhile, the hybrid NiFeGe (9 Å)/ MgO (3 Å) interlayers shows the highest SHA.
Our study provides a useful framework for understanding ultrahigh charge-to-spin conversion efficiencyand guidance on increasing it by optimizing the interlayer material for ultralow power SOT applications.