Interlayer Dzyaloshinskii-Moriya Interaction in Synthetic Ferrimagnets for Spiking Neural Networks

Interlayer Dzyaloshinskii-Moriya interaction (IL-DMI) in synthetic magnetic structures has attracted extensive interest for greatly facilitating deterministic spin-orbit torque (SOT)-driven information writing and topologically non-trivial 3D magnetic Hopfion forming. However, its distinct role in synthetic ferrimagnets (SFi) remains unexplored, where the conjunction of asymmetric magnetic moments and antisymmetric nature of IL-DMI leads to more diverse spin configurations and applications. Here, we reveal the unidirectional and chiral nature of IL-DMI in SFi, further unlocking application directions of IL-DMI in neuromorphic computing. Particularly, the IL-DMI-induced effective field increases approximately twentyfold while interacting with two asymmetric antiparallel-aligned moments, greatly facilitating future IL-DMI detection. Unlike previous digital-like switching, we find that the interplay of IL-DMI, SOT, and thermal effect gives rise to an analog-like switching behavior. Leveraging this, we develop an SOT-based non-probabilistic leaky-integrate-fire neuron device utilizing the micromagnetic analog-like switching model. Compared to probabilistic neurons, this provides a hardware support Spiking neural network, interlayer Dzyaloshinskii-Moriya interaction, spin-orbit torque, synthetic ferrimagnetsfor ultralow power, high-sparsity, and high-accuracy spiking neural networks.