Noise Measurements on MnSi thin films

Merlin Mitschek, David Schroeter, Dirk Menzel, Stefan Süllow, Jens Müller
2019 unpublished
Noise measurements are supposed to be a powerful tool to study the dynamical properties of a driven lattice of magnetic skyrmions. In analogy to the properties of driven superconducting vortices, broad-band and narrow band noise is expected to probe the microscopic pinning potential and lowfrequency dynamics of the skyrmion lattice. We present first measurements of fluctuation spectroscopy on epitaxial grown MnSi thin film samples, which are expected to show a larger amplitude of fluctuations
more » ... e of fluctuations due to their strongly reduced volume as compared to bulk systems and enhanced absolute resistance values. We observe generic 1/f -type noise, however with only a weak temperature dependence and no signatures of a magnetic skyrmion phase, which may be explained by electronic inhomogeneities or the absence of a well-defined skyrmionic phase in these samples subject to subtrate-induced strain. Upon approaching the helical magnetically ordered phase in zero field, we observe an enhancement of the 1/f -type fluctuations and twolevel switching of a characteristic energy, possibly related to the switching of magnetic grains/clusters.
doi:10.5075/epfl-iclab-icnf-269237 fatcat:2td3huhgtna7ljofceperfneki