Spin-flip switching of a nanoscale synthetic antiferromagnet by excitation of individual spin-wave modes*

Synthetic antiferromagnets (SAF) offer increased functionalization of spintronic devices, thus stimulating fundamental and application-driven research. Understanding and controlling critical phenomena of the SAF spin dynamics, such as magnetic switching, plays a central role. Here, we investigate magnetic switching of a nanoscale SAF with perpendicular order parameter, incorporated in a magnetic tunnel junction (MTJ) structure [1,2]. We drive the MTJ with microwave pulses and observe spin-flip switching of the SAF by resonant excitation of an individual magnon mode of the SAF. The magnon spectrum of the nanoscale SAF is discrete. Evaluation of the switching probability distributions shows that various modes from this spectrum can facilitate the switching. Moreover, it suggests a substantial contribution of the thermal spin-torque. The results point the way toward energy-efficient SAF-based applications and open avenues for functionalizing SAFs in nanoscale heterostructures.

[1] A. Etesamirad et al., ACS Appl. Mater. Interfaces 13, 20288 (2021)

[2] I. Barsukov et al., Sci. Adv. 5, eaav6943 (2019)