All van der Waals Three-Terminal SOT-MRAM Realized by Topological Ferromagnet Fe₃GeTe₂

Magnetic van der Waals (vdW) materials have attracted massive attention because of their academic interest and application potential for the past few years. Its main advantage is the intrinsic two-dimensionality, enabling much smaller devices of novel concepts. One particular exciting direction lies in the current-driven spin-orbit torque (SOT). Here, for the first time, all vdW three-terminal SOT memory is realized, employing the unique physics principle of gigantic intrinsic SOT of Fe3GeTe2 (FGT) and the well-known industry-adopted tunneling magnetoresistance (TMR) effect. The device operation procedure is designed and the FGT/h-BN/FGT vdW heterostructure is fabricated as a proof of concept. This device exhibits a classical TMR effect and unambiguously demonstrates the conception by precise performance as expected: the magnetic information of the top-FGT is written by current-driven SOT and read out by TMR separately. The writing and reading current paths are physically decoupled, enhancing the design and optimization flexibility substantially and further strengthening the device's endurance naturally. The work will prompt more expansive use of vdW magnets for spintronic applications.