UNDERSTANDING AND PREDICTING THE ELECTRONIC AND DYNAMIC BEHAVIOR OF NANOSCALE MAGNETIC RANDOM ACCESS MEMORY (MRAM) CELLS USING MICROMAGNETIC MODELLING AND SIMULATION

摘要

In recent years, micromagnetic simulation has evolved into a vital tool for understanding and optimizing the electronic and dynamic properties of magnetic structures on the nanometer scale. The main focus of current research has moved from establishment of correct models and simulation tools to understanding the results furnished by such tools, with the exception of two major fields that are currently given much attention. The first is the study of the interaction between the magnetization or spin of a ferromagnetic material with electric currents, and secondly the study of the dynamic properties in such nanomagnets when switching between different magnetization states, e.g., spin wave modes, damping, etc. We have adapted an existing simulation code by optimizing its performance for dynamic simulations, integrated a feature that computes one type of current-spin interaction, and computed the Fourier transformation intofrequency space thus revealing the spin wave modes of typical nanomagnetic structures. In this paper, we present the fundamental equations and methods implemented in the simulation of current-spin interactions and in the calculation of spin wave modes, as well as results from these simulations and computations.