3D Ferrimagnetic Device for Multi-Bit Storage and Efficient In-Memory Computing

摘要

In this letter, we propose a 3D spintronic device stacked by ferrimagnetic (FIM) alloy CoTb layers with a thickness gradient for realizing multi-bit storage and efficient in-memory computing (IMC). Firstly, spin-orbit torque (SOT) induced multi-level magnetization switching of a Pt/CoTb/W/CoTb/Pt stack is experimentally achieved and micromagnetically modeled. Furthermore, a 3D-FIM IMC device with multiple ferrimagnetic layers is constructed and analyzed. Its functionalities of ultra-dense storage and reconfigurable logic are both validated through micromagnetic studies. Due to the ultra-fast dynamics near the compensation point, this 3D-FIM IMC device can operate with ultra-low energy consumption (similar to 18 aJ) and ultra-high speed (similar to 25 ps).