Spintronics: Ionic Modulation of the Interfacial Magnetism in a Bilayer System Comprising a Heavy Metal and a Magnetic Insulator for Voltage-Tunable Spintronic Devices (Adv. Mater. 40/2018)

AbstractThe manipulation of magnetization in a metallic ferromagnet by using optical helicity has been much attracted attention for future opto-spintronic devices. The optical helicity–induced torques on the magnetization, optical spin torque, have been observed in ferromagnetic thin films recently. However, the interfacial effect of the optical spin torque in ferromagnet/nonmagnetic heavy metal heterostructures have not been addressed so far, which are widely utilized to efficiently control magnetization via electrical means. Here, we studied optical spin torque vectors in the ferromagnet/nonmagnetic heavy metal heterostructures and observed that in-plane field-like optical spin torque was significantly increased with decreasing ferromagnetic layer thicknesses. The interfacial field-like optical spin torque was explained by the optical Rashba–Edelstein effect caused by the structural inversion symmetry breaking. This work will aid in the efficient optical manipulation of thin film nanomagnets using optical helicity.

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Electrical manipulation of antiferromagnetic easy axis in IrMn/NiFe exchange-biased structures

10.21203/rs.3.rs-148179/v1 ◽

2021 ◽

Author(s):

Jaimin Kang ◽

Jeongchun Ryu ◽

Jong-Guk Choi ◽

Taekhyeon Lee ◽

Jaehyeon Park ◽

...

Keyword(s):

Heavy Metal ◽

Exchange Bias ◽

Easy Axis ◽

Inversion Symmetry ◽

Spin Orbit ◽

Key Technology ◽

Spintronic Devices ◽

Electrical Control ◽

Multi Level ◽

Electrical Manipulation

Abstract Electrical control of antiferromagnetic moment is a key technology of antiferromagnet-based spintronics, which promises favourable device characteristics of ultrafast operation and high-density integration compared to conventional ferromagnet-based devices. To date, the manipulation of antiferromagnetic moments has been demonstrated in epitaxial antiferromagnets with broken inversion symmetry or antiferromagnets interfaced with a heavy metal, in which spin-orbit torque (SOT) drives the antiferromagnetic domain wall. Here, we report electrical manipulation of the antiferromagnetic easy axis in IrMn/NiFe bilayers without a heavy metal. We show that the direction of the antiferromagnetic easy axis and associated exchange bias is gradually modulated between up to ±22 degrees by in-plane current, which is independent of the NiFe thickness, however. This suggests that spin currents arising in the IrMn layer exert SOTs on uncompensated antiferromagnetic moments at the interface and then rotate the antiferromagnetic moments coherently. Furthermore, the memristive features are preserved in sub-micron devices, facilitating nanoscale multi-level antiferromagnetic spintronic devices.

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Current-induced manipulation of exchange bias in IrMn/NiFe bilayer structures

Nature Communications ◽

10.1038/s41467-021-26678-x ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Jaimin Kang ◽

Jeongchun Ryu ◽

Jong-Guk Choi ◽

Taekhyeon Lee ◽

Jaehyeon Park ◽

...

Keyword(s):

Heavy Metal ◽

Domain Wall ◽

Electric Current ◽

Exchange Bias ◽

High Density ◽

Inversion Symmetry ◽

Spin Orbit ◽

Spintronic Devices ◽

Electrical Control ◽

Multi Level

AbstractThe electrical control of antiferromagnetic moments is a key technological goal of antiferromagnet-based spintronics, which promises favourable device characteristics such as ultrafast operation and high-density integration as compared to conventional ferromagnet-based devices. To date, the manipulation of antiferromagnetic moments by electric current has been demonstrated in epitaxial antiferromagnets with broken inversion symmetry or antiferromagnets interfaced with a heavy metal, in which spin-orbit torque (SOT) drives the antiferromagnetic domain wall. Here, we report current-induced manipulation of the exchange bias in IrMn/NiFe bilayers without a heavy metal. We show that the direction of the exchange bias is gradually modulated up to ±22 degrees by an in-plane current, which is independent of the NiFe thickness. This suggests that spin currents arising in the IrMn layer exert SOTs on uncompensated antiferromagnetic moments at the interface which then rotate the antiferromagnetic moments. Furthermore, the memristive features are preserved in sub-micron devices, facilitating nanoscale multi-level antiferromagnetic spintronic devices.

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