Verilog-A-Based Analytical Modeling of Vortex Spin-Torque Nano Oscillator

Topological spin textures are the next-generation spintronic building blocks for storing and processing information because of their controllable formation and annihilation. Memory, logic, and neuromorphic computing applications are reported using such devices having 2-D and 3-D spin textures, namely, vortex, skyrmions, localized bullet, and so on. A robust device-to-circuit-to-system level design is required for developing a neural network (NN) or a neuromorphic computing system (NCS) using these spin devices. Hence, in this work, we present a Verilog-A-based analytical model of a vortex spin-torque nano oscillator (V-STNO) for enabling circuit-level simulation. The model presented here is functional for both linear and nonlinear dynamics of the magnetic vortex core. The nonlinear dynamics show the formation and annihilation of the magnetic vortex depending on its critical currents. Furthermore, the developed model is analyzed for the nanopillar’s diameter and free layer thickness variations. Moreover, an investigation of the temperature effect on the device performance for a range of −40°C to 140 °C is carried out.