Cascadable in-memory computing based on symmetric writing and readout.

Wang, Lizheng; Xiong, Junlin; Cheng, Bin; Dai, Yudi; Wang, Fuyi; Pan, Chen; Cao, Tianjun; Liu, Xiaowei et al. · Sci Adv · 2022

basic_science · Level V

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Abstract

The building block of in-memory computing with spintronic devices is mainly based on the magnetic tunnel junction with perpendicular interfacial anisotropy (p-MTJ). The resulting asymmetric write and readout operations impose challenges in downscaling and direct cascadability of p-MTJ devices. Here, we propose that a previously unimplemented symmetric write and readout mechanism can be realized in perpendicular-anisotropy spin-orbit (PASO) quantum materials based on Fe<sub>3</sub>GeTe<sub>2</sub> and WTe<sub>2</sub>. We demonstrate that field-free and deterministic reversal of the perpendicular magnetization can be achieved using unconventional charge-to-<i>z</i>-spin conversion. The resulting magnetic state can be readily probed with its intrinsic inverse process, i.e., <i>z</i>-spin-to-charge conversion. Using the PASO quantum material as a fundamental building block, we implement the functionally complete set of logic-in-memory operations and a more complex nonvolatile half-adder logic function. Our work highlights the potential of PASO quantum materials for the development of scalable energy-efficient and ultrafast spintronic computing.