  Supplementary information for our manuscript, entitled 'Spontaneous Skyrmion
Ground States of Magnetic Metals', cond-mat/0603103, is presented. The physical
nature of the gradient terms of our generalized micromagnetic model for
ferromagnets with softened longitudinal fluctuations is explained. The
relationship of our micromagnetic model with the spin fluctuation theory of
itinerant-electron magnets is discussed. Experimental estimates of the
parameter eta, which accounts for an effective reduced longitudinal stiffness,
are presented for real materials from published polarized neutron scattering
experiments on EuS, Ni and MnSi. The available experimental data clearly show
that eta is significantly reduced for the latter two systems. It is suggested
that particle-hole excitations are at the root of this longitudinal softness in
itinerant-electron ferromagnets. The current status of the experimental
evidence supporting spontaneous, amorphous skyrmion textures in MnSi and other
materials is reviewed. Finally, we also address the general potential of
skyrmion textures in chiral magnets for other fields of physics.
