Topological spin memory of antiferromagnetically coupled skyrmion pairs in Co/Gd/Pt multilayers

Abstract

Magnetic skyrmions are topologically protected spin textures that have attracted considerable interest recently. This paper reports the discovery of a topological spin memory effect, which provides a promising new avenue for information encryption and recovery. The authors demonstrate experimentally that antiferromagnetically (AFM)-coupled bubble skyrmion pairs stabilized in a Co/Gd/Pt multilayered film at room temperature evolve into complex in-plane spin textures as the temperature is lowered and then reform completely when warmed back up. Simulations show that Dzyaloshinskii-Moriya interactions play a key role in this spin memory effect and reveal that the topological charge is preserved throughout the spin reorientation transition and recovery.