Polarized small-angle neutron scattering study of skyrmions in bulk nanocrystalline MnSi

It is crucial to understand the fundamental physics behind the origin and stability of skyrmions due to their potential for various quantum applications. It is also equally important to develop efficient experimental techniques to detect skyrmions in diverse material forms, such as thin films, single crystals, or nanoparticles. While attempts have been made to stabilize skyrmions in a wider temperature and magnetic field range e.g. by reducing the system dimensionality, conclusive evidence for the skyrmion phase in low-dimensional systems remains elusive. To advance the existing knowledge in this field, we propose to investigate the polarized small-angle neutron scattering (SANS) cross section of nanocrystalline MnSi below its transition temperature. Based on micromagnetic simulations, we anticipate observing a distinct signature of skyrmions in the antisymmetric part of the polarized SANS cross section, arising from the nonzero chirality and the complex magnetic structure of skyrmions. This approach has not been previously employed to detect the diffuse scattering signal due to skyrmions in nanoparticles. Therefore, this experiment will establish polarized SANS as a unique technique to identify skyrmions in various compound forms, including single crystals, polycrystals, thin films, or nanoparticles.