Anisotropy-dependent decay of room temperature metastable skyrmions and a nascent double-$q$ spin texture in Co$_{8}$Zn$_{9}$Mn$_{3}$

Chiral cubic Co-Zn-Mn magnets exhibit diverse topological spin textures, including room-temperature skyrmion phases and robust far-from-equilibrium metastable states. Despite recent advances in understanding metastable skyrmions, the interplay between compositional disorder and varying magnetic anisotropy on the stability and decay of metastable textures, particularly near room temperature, remains incompletely understood. In this work, the equilibrium and metastable skyrmion formation in Co$_{8}$Zn$_{9}$Mn$_{3}$ is examined, revealing transformations between distinct metastable spin textures induced by temperature and magnetic field. At room temperature, the decay dynamics of metastable skyrmions exhibits a strong dependence on magnetic anisotropy, showcasing a route towards tailoring relaxation behavior. Furthermore, a nascent double-$q$ spin texture, characterized by two coexisting magnetic modulation vectors $q$, is identified as a minority phase alongside the conventional triple-$q$ hexagonal skyrmion lattice. This double-$q$ texture can be quenched as a metastable state, suggesting both its topological character, and its role as a potential intermediary of metastable skyrmion decay. These findings provide new insights into the tunability of equilibrium and metastable topological spin textures via chemical composition and magnetic anisotropy, offering strategies for designing materials with customizable and dynamic skyrmion properties for advanced technological applications.