Low-Field Magnetic Anisotropy of Sr2IrO4

Abstract Magnetic anisotropy in strontium iridate (Sr2IrO4) is essential because of its strong spin-orbit coupling and crystal field effect. In this study, we investigated the detailed mapping of the out-of-plane (OOP) magnetic anisotropy in Sr2IrO4 for different sample orientations using torque magnetometry measurements in the low-magnetic-field region before the isospins are fully ordered. Dominant in-plane anisotropy was identified at low fields, confirming the b axis as an easy magnetization axis. Based on the fitting analysis of the strong uniaxial magnetic anisotropy, we observed that the main anisotropic effect arises from a spin–orbit-coupled magnetic exchange interaction that affects the OOP interaction. The interlayer exchange interaction results in additional anisotropic terms owing to the tilting of the isospins. Our results are relevant for understanding OOP magnetic anisotropy and provide a new way to analyze the effects of spin–orbit-coupling and interlayer magnetic exchange interactions. This study provides a new insight into the understanding of bulk magnetic, magneto-transport, and spintronic behavior of Sr2IrO4 for future studies.

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Low-field Magnetic Anisotropy of Sr2IrO4

Journal of Physics Condensed Matter ◽

10.1088/1361-648x/ac484d ◽

2022 ◽

Author(s):

Muhammad Nauman ◽

Tayyaba Hussain ◽

Joonyoung Choi ◽

Nara Lee ◽

Young Jai Choi ◽

...

Keyword(s):

Magnetic Anisotropy ◽

Exchange Interaction ◽

Exchange Interactions ◽

Orbit Coupling ◽

Spin Orbit Coupling ◽

Spin Orbit ◽

Easy Magnetization ◽

Magnetic Exchange ◽

Crystal Field Effect ◽

Out Of Plane

Abstract Magnetic anisotropy in strontium iridate (Sr2IrO4) is essential because of its strong spin–orbit coupling and crystal field effect. In this paper, we present a detailed mapping of the out-of-plane (OOP) magnetic anisotropy in Sr2IrO4 for different sample orientations using torque magnetometry measurements in the low-magnetic-field region before the isospins are completely ordered. Dominant in-plane anisotropy was identified at low fields, confirming the b axis as an easy magnetization axis. Based on the fitting analysis of the strong uniaxial magnetic anisotropy, we observed that the main anisotropic effect arises from a spin–orbit-coupled magnetic exchange interaction affecting the OOP interaction. The effect of interlayer exchange interaction results in additional anisotropic terms owing to the tilting of the isospins. The results are relevant for understanding OOP magnetic anisotropy and provide a new way to analyze the effects of spin–orbit-coupling and interlayer magnetic exchange interactions. This study provides insight into the understanding of bulk magnetic, magnetotransport, and spintronic behavior on Sr2IrO4 for future studies.

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Layer- and gate-tunable spin-orbit coupling in a high-mobility few-layer semiconductor

Science Advances ◽

10.1126/sciadv.abe2892 ◽

2021 ◽

Vol 7 (5) ◽

pp. eabe2892

Author(s):

Dmitry Shcherbakov ◽

Petr Stepanov ◽

Shahriar Memaran ◽

Yaxian Wang ◽

Yan Xin ◽

...

Keyword(s):

Electric Field ◽

High Mobility ◽

Orbit Coupling ◽

Spin Splitting ◽

Spin Orbit Coupling ◽

Spin Orbit ◽

Quantum Oscillations ◽

Out Of Plane ◽

Order Of Magnitude ◽

Spin Degeneracy

Spin-orbit coupling (SOC) is a relativistic effect, where an electron moving in an electric field experiences an effective magnetic field in its rest frame. In crystals without inversion symmetry, it lifts the spin degeneracy and leads to many magnetic, spintronic, and topological phenomena and applications. In bulk materials, SOC strength is a constant. Here, we demonstrate SOC and intrinsic spin splitting in atomically thin InSe, which can be modified over a broad range. From quantum oscillations, we establish that the SOC parameter α is thickness dependent; it can be continuously modulated by an out-of-plane electric field, achieving intrinsic spin splitting tunable between 0 and 20 meV. Unexpectedly, α could be enhanced by an order of magnitude in some devices, suggesting that SOC can be further manipulated. Our work highlights the extraordinary tunability of SOC in 2D materials, which can be harnessed for in operando spintronic and topological devices and applications.

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