Novel Magnetic‐Field‐Free Switching Behavior in vdW‐Magnet/Oxide Heterostructure

Abstract

Abstract Magnetization switching by charge current without a magnetic field is essential for device applications and information technology. It generally requires a current‐induced out‐of‐plane spin polarization beyond the capability of conventional ferromagnet/heavy‐metal systems, where the current‐induced spin polarization aligns in‐plane orthogonal to the in‐plane charge current and out‐of‐plane spin current. Here, a new approach is demonstrated for magnetic‐field‐free switching by fabricating a van‐der‐Waals magnet and oxide Fe 3 GeTe 2 /SrTiO 3 heterostructure. This new magnetic‐field‐free switching is possible because the current‐driven accumulated spins at the Rashba interface precess around an emergent interface magnetism, eventually producing an ultimate out‐of‐plane spin polarization. This interpretation is further confirmed by the switching polarity change controlled by the in‐plane initialization magnetic fields with clear hysteresis. Van‐der‐Waals magnet and oxide are successfully combined for the first time, especially taking advantage of spin‐orbit torque on the SrTiO 3 oxide. This allows this study to establish a new way of magnetic field‐free switching. This work demonstrates an unusual perpendicular switching application of large spin Hall angle materials and precession of accumulated spins, and in doing so, opens up a new field and opportunities for van‐der‐Waals magnets and oxide spintronics.