Electronic Noise in Magnetic Materials and Devices

Abstract

With the development of magnetic devices and new materials for spin electronics on the sub-micron scale, we consider the relevant properties of electronic noise in magnetic solid-state microstructures. We review the most common types of electronic fluctuations in materials, namely, thermal noise, shot noise, 1/f noise and random telegraph noise. In each case, the discussion is illustrated by recent reports on electronic noise in magnetic materials and devices. We show that the resistance fluctuation measurement is an unique tool to probe the dynamics of magnetic instabilities and their coupling to the charge carriers via spin dependent scattering processes on a nanometric scale. We finally consider electronic noise in promising materials and devices for spin electronic applications like half metallic oxides, CMR perovskites and GMR-based magnetic sensors. Comments on recent results point out fundamental properties of the electronic and magnetic ground states which can be extracted from noise measurements. Special attention is paid to the noise behaviour and the signal-to-noise ratio in magneto-electronic applications.