Electronic noise in magnetic low-dimensional materials and nanostructures

Abstract After a brief review underlining the power of electronic noise studies to probe local magnetic instabilities, we present new data in three different systems in terms of dimensionality and magnetic ordering: the first results we present deal with low-frequency longitudinal and Hall resistance fluctuations in Ni nanostructures, where we address the questions of the inhomogeneous behavior of the noise at a nanometric scale. In order to get some insight into the atomic process, we report on noise generated in atomic contacts of Ni obtained by the break junction technique. And finally, we present the first electronic noise study in a one-dimensional frustrated magnetic Ca 3 Co 2 O 6 single crystal composed of parallel Co spin chains. From the magnetic noise analysis, we discuss the interplay between the low-temperature three-dimensional magnetic ordering and the spin-dependent hopping conductivity on the Co sites.