Field-Free Spin-Orbit Torque Driven Perpendicular Magnetization Switching of Ferrimagnetic Layer Based on Noncollinear Antiferromagnetic Spin Source

The utilization of novel noncollinear antiferromagnetic materials holds great promise for the development of energy-efficient spintronic devices. However, only a few studies have reported on the all-electrical control of perpendicular magnetization switching using noncollinear antiferromagnets as the spin source, and the underlying mechanism behind the unconventional spin-orbit torque (SOT) is still a topic of debate. In this work, deterministic perpendicular magnetization switching in Mn3Sn/CoTb bilayers is successfully achieved. Compared to the control samples with heavy metal as the spin source, the critical switching current density is over one order of magnitude reduced, indicating an enhanced efficiency of the out-of-plane charge-to-spin conversion in the textured Mn3Sn films. The influence of film thickness and growth temperature on the efficiency of different spin polarizations suggests potential roles of crystal quality and spin texture in spin diffusion with different spin polarization directions. These findings provide valuable insights into the crystal structure, spin-orbit torque effects, and charge-to-spin conversion in Mn3Sn films, highlighting the importance of understanding interface and bulk contributions in antiferromagnetic spin transport phenomena. The authors demonstrate deterministic perpendicular magnetization switching in Mn3Sn/CoTb bilayers by employing a textured Mn3Sn film as the spin source. This study emphasizes the significant contribution of the out-of-plane polarized spin current (sigma z) generated from Mn3Sn to the spin-orbit torque (SOT) effect. This underscores the critical role of crystal quality and strain in controlling spin diffusion with different spin polarizations.image

Automated summary

The study demonstrates deterministic perpendicular magnetization switching in Mn3Sn/CoTb bilayers by employing a textured Mn3Sn film as the spin source. It highlights the significant contribution of the out-of-plane polarized spin current (sigma z) generated from Mn3Sn to the spin-orbit torque (SOT) effect. This underscores the critical role of crystal quality and strain in controlling spin diffusion with different spin polarizations.