  Chiral magnetic states in two-dimensional (2D) layered noncentrosymmetric
magnets, which are promising advanced spintronic materials, are usually
attributed to Dzyaloshinskii-Moriya interactions (DMI). However, the role of
underlying higher-order spin couplings in determining the properties of chiral
spin textures has much less reported. In this work, taking the
lithium-decorated monolayer CrTe$_{2}$ (monolayer LiCrTe$_{2}$) as an example,
we develop a first-principles-based comprehensive spin model constructed by
using the symmetry-adapted cluster expansion method. Based on this spin model,
we identify the ground state of monolayer LiCrTe$_{2}$ as a chiral spin spiral
state, which can further assemble macroscopic chiral labyrinth domains (LD)
under zero-field conditions as well as evolve into skyrmions under a finite
magnetic field. Moreover, higher-order biquadratic and three-site interactions
are identified to be responsible for modulating both the size and the field
stability of the spin spiral state. Our study sheds light on complex magnetic
couplings in 2D magnets.
