Analysis of magnetic noises in two-dimensional magnetic recording readers

A model is introduced in this paper to describe the effects of thermal magnetic noises in the read sensor under off-track reading conditions taking into account the influence of the magnetic field generated by the recorded magnetization patterns on the medium. Our numerical studies show that there exist additional noises in the hard biased reader, depending on recorded patterns on the magnetic media. The influence of the recorded magnetic patterns is not only on the variation in reader resistance but also on the high frequency noises caused primarily by the thermal fluctuations. The theoretical analysis is based on the micromagnetic modeling of the state of magnetization in read sensor taking into account of its external magnetic fields due to both the hard bias and the media magnetization patterns. The effect of the thermal agitation of the gyromagnetical precession of magnetizations is evaluated by considering the angular magnetic noise.