Study on generation and high-speed driving of skyrmion in the multilayered films with antiferromagnetic coupling

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K03836
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
• Research Institution: Nagoya Institute of Technology
• Principal Investigator: Tanaka Masaaki 名古屋工業大学, 工学(系)研究科(研究院), 准教授 (50508405)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: スピントロニクス

Outline of Final Research Achievements

The stabilization of the skyrmion-like bubble domains (BDs) using antiferromagnetic interlayer exchange coupling (IEC) of "ferromagnetic /nonmagnetic /ferromagnetic" wires was investigated. Micromagnetic simulations clarified that the BDs can be stabilized using antiferromagnetic IEC in the wires without the interfacial Dzyaloshinskii-Moriya interaction and that the driven direction of the BDs via spin-orbital torque (SOT) can become parallel to the electric current direction. It was also found that the magnetic moment in the domain walls (DWs) depends on the antiferromagnetic IEC strength, and the stability of the Neel-type DW increases with an increase in the antiferromagnetic IEC strength. As a consequence of this stability, the SOT affects effectively on the magnetic moment of the DWs and the DW velocity increases. These results imply that the antiferromagnetic IEC can be applied for the stabilization of the BDs and the control of the DW velocity in magnetic domain-based memories.

Free Research Field

磁性物理学

Academic Significance and Societal Importance of the Research Achievements

反強磁性結合を有する細線では磁気スキルミオンバブル磁区(BD)が安定化でき、細線を流れる電流方向に対してBDが平行に移動できることを明らかにした。反強磁性結合を用いることでBDの安定性を自由に制御でき、また細線上のBDを電流で安定して駆動できるなど、本研究から得られた知見は磁気メモリーの研究に対して有益な情報を与えると考えている。また、反強磁性結合を用いることで磁壁駆動の速度が上昇することが明らかになっており、この研究成果は磁壁駆動メモリーの省電力化・高速化に貢献すると考えている。