Current-induced Dynamics of Easy-Plane Antiferromagnets

Abstract

Antiferromagnetic memory devices are expected to be very fast, stable, dense and energy-efficient, making them promising for the next generation non-volatile random-access memory. However, in antiferromagnets, it used to be challenging to accurately understand the current-induced dynamics, especially the spin-orbit-torque switching dynamics. To realize a practical antiferromagnetic memory device, we must overcome the challenge.

In this PhD Thesis, I discussed about the systematic and quantitative study of a model material, collinear easy-plane antiferromagnetic insulator α-Fe2O3 covered by Pt, for non-spin-orbit-torque switching mechanisms, magnon spin transport, and finally, the long-anticipated damping-like-torque switching, and the method to quantitatively characterize the spin-orbit torques. And I also discussed about the study about the damping-like-torque switching of a non-collinear easy-plane antiferromagnetic metal Mn3Sn, and the handedness anomaly of the switching direction.

These studies deepen the scientific understandings of spin-orbit torque dynamics in antiferromagnets, and pave the way to real-life applications of antiferromagnetic memory devices.