Antiferromagnet-based spintronic functionality by controlling isospin domains in a layered perovskite iridate

Abstract

The novel electronic state of the canted antiferromagnetic (AFM) insulator, strontium iridate (Sr2IrO4) has been well described by the spin-orbit-entangled isospin Jeff = 1/2, but the role of isospin in transport phenomena remains poorly understood. In this study, antiferromagnet-based spintronic functionality is demonstrated by combining unique characteristics of the isospin state in Sr2IrO4. Based on magnetic and transport measurements, large and highly anisotropic magnetoresistance (AMR) is obtained by manipulating the antiferromagnetic isospin domains. First-principles calculations suggest that electrons whose isospin directions are strongly coupled to in-plane net magnetic moment encounter the isospin mismatch when moving across antiferromagnetic domain boundaries, which generates a high resistance state. By rotating a magnetic field that aligns in-plane net moments and removes domain boundaries, the macroscopically-ordered isospins govern dynamic transport through the system, which leads to the extremely angle-sensitive AMR. As with this work that establishes a link between isospins and magnetotransport in strongly spin-orbit-coupled AFM Sr2IrO4, the peculiar AMR effect provides a beneficial foundation for fundamental and applied research on AFM spintronics.

Advanced Materials, online published (2018)

References in corpus (11)

• Antiferromagnetic spintronics
• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4
• Electrical switching of an antiferromagnet
• Magnetization switching by spin-orbit torque in an antiferromagnet/ferromagnet bilayer system
• Room-temperature antiferromagnetic memory resistor
• Multiple-stable anisotropic magnetoresistance memory in antiferromagnetic MnTe
• The magnetic and crystal structures of Sr2IrO4: A neutron diffraction study
• Anisotropic magnetoresistance in antiferromagnetic semiconductor Sr2IrO4 epitaxial heterostructure
• Neutron scattering study of correlated phase behavior in Sr2IrO4
• Isothermal anisotropic magnetoresistance in antiferromagnetic metallic IrMn

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• Giant anisotropic magnetoresistance and nonvolatile memory in canted antiferromagnet Sr2IrO4
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• Spin-flip-driven giant magneto-transport in A-type antiferromagnet NaCrTe2
• Comprehensive Control of Metamagnetic Transition of Antiferromagnetic Mott Insulator Sr2IrO4 by in-situ Anisotropic Strain
• Anomalous Magnetoresistance due to Longitudinal Spin Fluctuations in a Jeff = 1/2 Mott Semiconductor
• Controllable emergent spatial spin modulation in Sr2IrO4 by in situ shear strain
• Epitaxial growth and antiferromagnetism of Sn-substituted perovskite iridate SrIr${}_{0.8}$Sn${}_{0.2}$O${}_3$
• Giant anisotropic magnetoresistance with dual-four-fold symmetry in CaMnO3/CaIrO3 heterostructures