  The impact of magnetic anisotropy on the skyrmion lattice (SkL) state in
cubic chiral magnets has been overlooked for long, partly because a
semi-quantitative description of the thermodynamically stable SkL phase pocket
forming near the Curie temperature could be achieved without invoking
anisotropy effects. However, there has been a range of phenomena reported
recently in these materials, such as the formation of low-temperature tilted
conical and SkL states as well as temperature-induced transformations of
lattice geometry in metastable SkL states, where anisotropy was suspected to
play a key role. To settle this issue on experimental basis, we quantified the
cubic anisotropy in a series of CoZnMn-type cubic chiral magnets. We found that
the strength of anisotropy is highly enhanced towards low temperatures in all
the compounds, moreover, not only the magnitude but also the character of cubic
anisotropy drastically varies upon changing the Co/Mn ratio. We correlate these
changes with temperature- and composition-induced variations of the helical
modulation vectors, the anharmonicity and structural rearrangements of the
metastable SkLs and the spin relaxation rates. Similar systematic studies on
magnetic anisotropy may not only pave the way for a quantitative and unified
description of the stable and metastable modulated spin textures in cubic
chiral magnets but would also help exploring further topological spin textures
in this large class of skyrmion hosts.
