Probe of skyrmion phases and dynamics in MnSi via the magnetoelectric effect in a composite configuration

We have developed a sensitive technique to probe the magnetic skyrmion phases and dynamics by employing the interfacial coupling effect in a magnetoelectric composite configuration. The study on a MnSi single crystal sample using this technique provides clear evidence for the skyrmion lattice phase and coexistence of skyrmion and conical phase. Above the Curie temperature T-C, a region with strong spin fluctuation is revealed as well. By tuning the density of skyrmion or disorder, a transition from the skyrmion lattice to skyrmion-conical coexisting phase is observed. The observation is in good agreement with a theoretical model which predicts the dissipation behavior in the coexistence phase.