Staggered field driven domain walls motion in antiferromagnetic heterojunctions

In this work, we study the antiferromagnetic (AFM) spin dynamics in heterostructures which consist of two coupled AFM layers, i.e., AFM1 layers (describing CuMnAs or Mn2Au) with field-like Neel spin-orbit torque (NSOT) and AFM2 layers with easy-axis anisotropy orthogonal to that in AFM1 layers. Our micromagnetic simulations demonstrate that through the interface coupling, the AFM2 domain wall (DW) can be effectively driven by the AFM1 DW which is driven by the electrical current induced NSOT [Gomonay et al., Phys. Rev. Lett. 117, 017202 (2016)]. Furthermore, the two DWs detach from each other when the torque increases above a critical value. The critical field and the highest possible velocity of the AFM2 DW depend on several factors, which are investigated and discussed in detail. Based on the calculated results, we propose a method of efficiently modulating the multi DWs in antiferromagnets, which definitely provides useful information for future AFM spintronics device design. Published by AIP Publishing.