Polarity-tunable field-free room-temperature spin orbit torque switching via topological symmetry breaking in an all-vdW heterostructure for spin logic applications.

Abstract

Two-dimensional ferromagnetic materials hold great promise for advancing low-power, high-integrated spintronic devices due to their atomic flat surfaces and versatile interfacial modulation. However, achieving a combination of room-temperature, field-free spin-orbit torque switching with tunable polarity in wafer-scale vdW heterostructures remains a significant challenge. Here, we demonstrate polarity-tunable, field-free spin-orbit torque switching in an all-vdW Bi₂Te₃/Fe₄GeTe₂ heterostructure, grown by molecular beam epitaxy. Interfacial coupling induces perpendicular magnetic anisotropy in Bi₂Te₃/Fe₄GeTe₂ interface, while the rest in-plane magnetic anisotropy component of Fe₄GeTe₂ breaks the inversion symmetry, enabling field-free switching. By modulating the direction of in-plane component, magnetic switching with different polarity could be achieved at low current density (~1.55×10⁶ A/cm²). This allows for 16 reconfigurable Boolean logic functions in a single device, paving a pathway for energy-efficient 2D spintronic memory and logic systems. Our findings highlight the potential of all-vdW spin-orbit torque devices to revolutionize spintronics with scalable, room-temperature electronic control.