Observation of strong bulk damping-like spin-orbit torque in chemically disordered ferromagnetic single layers

Abstract

Strong damping-like spin-orbit torque (τDL) has great potential for enabling ultrafast energy-efficient magnetic memories, oscillators, and logic. So far, the reported τDL exerted on a thin-film magnet must result from an externally generated spin current or from an internal non-equilibrium spin polarization in noncentrosymmetric GaMnAs single crystals. Here, we for the first time demonstrate a very strong, unexpected τDL from current flow within ferromagnetic single layers of chemically disordered, face-centered-cubic CoPt. We establish that the novel τDL is a bulk effect, with the strength per unit current density increasing monotonically with the CoPt thickness, and is insensitive to the presence or absence of spin sinks at the CoPt surfaces. This τDL most likely arises from a net transverse spin polarization associated with a strong spin Hall effect (SHE), while there is no detectable long-range asymmetry in the material. These results broaden the scope of spin-orbitronics and provide a novel avenue for developing single-layer-based spin-torque memory, oscillator, and logic technologies.

This manuscript is a primary version, see Advanced Functional Materials for the updated manuscript and for the supporting information

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Cited by in corpus (8)

• Maximizing Spin-Orbit Torque Generated by the Spin Hall Effect of Pt
• Switching of Perpendicular Magnetization by Spin-Orbit Torque
• Magnetization switching in polycrystalline Mn3Sn thin film induced by self-generated spin-polarized current
• Quantifying the Dzyaloshinskii-Moriya Interaction Induced by the Bulk Magnetic Asymmetry
• Lack of simple correlation between switching current density and spin-orbit torque efficiency of perpendicularly magnetized spin-current generator/ferromagnet heterostructures
• Unveiling the mechanism of bulk spin-orbit torques within chemically disordered Fe${}_x$Pt${}_{1-x}$ single layers
• Current-induced perpendicular effective magnetic field in magnetic heterostructures
• Efficient generation of out-of-plane polarized spin current in polycrystalline heavy metal devices with broken electric symmetries