A unified understanding of planar spiral domain walls in ferromagnet/antiferromagnet/ferromagnet trilayers

Domain walls (DWs) in antiferromagnets (AFMs) usually show unique internal spin textures and behaviors compared to their counterparts in ferromagnets (FMs). Besides the well-known experimental difficulties in detecting AFM DWs, theoretical understanding of their complex behaviors is still to be elaborated. Here we develop an analytical model to describe planar spiral DWs in an AFM sandwiched between two FM layers. By examining the system’s energy profiles in its configuration space, we construct a phase diagram of the system and show how the behaviors of the DWs depend critically on the interlayer coupling between FMs and AFMs. Our results clarify the recent inconsistent experimental observations on the AFM planar spiral DWs, and provide new insights toward AFM spintronic applications.