Current-controlled magnetism and resultant nonvolatile multi-state memory devices in Co-doped van der Waals magnet

The control of van der Waals (vdW) magnets by spin–orbit torque (SOT) induced by in-plane current holds great potential for next-generation spintronic applications, offering high-density, ultrafast, and low-power solutions. However, the generation of SOT typically requires both strong spin–orbit coupling and broken inversion symmetry, which are often achieved in ferromagnet/heavy metal heterostructures. Here, we demonstrate highly tunable magnetic states and coercivity in a single vdW ferromagnet, (Fe0.74Co0.26)3GeTe2, driven by SOT. The SOT originates from the broken inversion symmetry, as evidenced by the second-order nonlinear Hall effect. This facilitates nonvolatile magnetization switching in (Fe0.74Co0.26)3GeTe2 nanodevices controllable with a low current density (∼106 A/cm2). Furthermore, we achieve up to 8 electrically switchable multi-level states, significantly enhancing information storage density and reducing computational costs. Our findings advance the electrical control of ferromagnetism and its integration into spintronic devices.