Noise and magnetic domain fluctuations in spin-valve GMR heads

Random telegraph noise (RTN) can be observed in the voltage across some spin valve heads over particular ranges of bias current, magnetic field and temperature. The detailed dependence of the RTN signal on these parameters demonstrates that the noise is due to thermally activated magnetic domain fluctuations. Further, a comparison of the effects of applied magnetic field and bias current provides information about the physical location of the magnetic domains within the head.