Non-centrosymmetric magnetism in twisted bilayer CrI₃

Twist engineering of van der Waals magnets emerges as a novel platform for manipulating exotic magnetic states. However, the complicated form of spin interactions in the large moiré superlattice obstructs the concrete understanding of such spin systems. To tackle this problem, we developed a generic ab-initio spin Hamiltonian for twisted bilayer magnets for the first time. Our atomistic model reveals several unprecedented features and phases including AB sublattice symmetry breaking and, in turn, skyrmion phase. That is to say, twisting van der Waals magnets introduces a promising route to realize non-centrosymmetric magnetism.