Implementation of Highly Reliable and Energy‐Efficient Nonvolatile In‐Memory Computing using Multistate Domain Wall Spin–Orbit Torque Device

Abstract

Emerging in‐memory computing (IMC) technology promises to tackle the memory wall bottleneck in modern systems. Promoted as a promising building block, nonvolatile spin–orbit torque (SOT) memory devices with sub‐ns and sub‐pJ processing capabilities are thereby extensively pursued. Herein, a new type of domain wall device is experimentally presented with multistates driven by nonvolatile SOT and Dzyaloshinskii–Moriya interaction, enabling time and energy‐efficient IMC with a full adder (FA) implementation based on magnetic tunnel junctions. Complementary micromagnetic and device–circuit cosimulation results show that the write/read latency of the proposed FA can be shortened to 1.25 ns/0.22 ns with an averaged writing energy of 8.41 fJ bit−1, and the overall dynamic power is 26.25 μW, which is 4.43–51.96 times lower than state‐of‐the‐art alternatives. Moreover, the developed architecture can perform all 16 Boolean logic functions, warranting an extensive arithmetic operation. The experimental, micromagnetic, and circuit‐level simulation results show great potential in both fundamental research and new trajectories in technology development for nonvolatile in‐memory computing applications.

Keywords

• domain wall-magnetic heterostructures
• Dzyaloshinskii–Moriya interaction
• multistate
• nonvolatile in-memory computing
• spin–orbit torque