Micromagnetic model is a very useful tool in the design and analysis of magnetic recording system. The micromagnetic principle and numerical method are described. Magnetic writing and reading processes are simulated by the model. Emphasis is on the modeling of giant magnetoresistive (GMR) readback sensor, which is the most important technology behind the phenomenal areal density increase of hard disk drives in recent years. Futher development of micromagnetic model is discussed.
