Quantifying Spin-Orbit Torques in Antiferromagnet/Heavy Metal Heterostructures

Abstract

The effect of spin currents on the magnetic order of insulating antiferromagnets (AFMs) is of fundamental interest and can enable new applications. Toward this goal, characterizing the spin-orbit torques (SOT) associated with AFM/heavy metal (HM) interfaces is important. Here we report the full angular dependence of the harmonic Hall voltages in a predominantly easy-plane AFM, epitaxial c-axis oriented $\alpha$-Fe${}_2$O${}_3$ films, with an interface to Pt. By modeling the harmonic Hall signals together with the $\alpha$-Fe${}_2$O${}_3$ magnetic parameters, we determine the amplitudes of field-like and damping-like SOT. Out-of-plane field scans are shown to be essential to determining the damping-like component of the torques. In contrast to ferromagnetic/heavy metal heterostructures, our results demonstrate that the field-like torques are significantly larger than the damping-like torques, which we correlate with the presence of a large imaginary component of the interface spin-mixing conductance. Our work demonstrates a direct way of characterizing SOT in AFM/HM heterostructures.

References in corpus (9)

• Theory of spin Hall magnetoresistance
• Roadmap of spin-orbit torques
• Writing and Reading antiferromagnetic Mn${}_2$Au: Néel spin-orbit torques and large anisotropic magnetoresistance
• Spin pumping and spin-transfer torques in antiferromagnets
• Negative spin Hall magnetoresistance of Pt on the bulk easy-plane antiferromagnet NiO
• Maximizing Spin-Orbit Torque Generated by the Spin Hall Effect of Pt
• Identification of Néel vector orientation in antiferromagnetic domains switched by currents in NiO/Pt thin films
• Direct Imaging of Electrical Switching of Antiferromagnetic Néel Order in $\alpha$-Fe${}_2$O${}_3$ Epitaxial Films
• Theory of Harmonic Hall Responses of Spin-Torque Driven Antiferromagnets

Cited by in corpus (10)

• Intrinsic Nonlinear Hall Detection of the Néel Vector for Two-Dimensional Antiferromagnetic Spintronics
• Third Harmonic Characterization of Antiferromagnetic Heterostructures
• Thermal effects in spintronic materials and devices: an experimentalist's guide
• Absence of cross-sublattice spin pumping and spin-transfer torques in collinear antiferromagnets
• Estimation of spin-orbit torques in the presence of current-induced magnon creation and annihilation
• Theory of Harmonic Hall Responses of Spin-Torque Driven Antiferromagnets
• Large spin-orbit torque in a-plane $\alpha$-Fe${}_2$O${}_3$/Pt bilayers
• Coherent Spin Pumping Originated from Sub-Terahertz Néel Vector Dynamics in Easy Plane α-Fe2O3/Pt
• Characterizing Spin-Orbit Torques by Tensorial Spin Hall Magnetoresistance
• Magnetic precession induced spin accumulation in collinear antiferromagnets