Engineering a Skyrmion Crystal in Ferromagnetic/Antiferromagnetic Bilayers Based on Magnetic Frustration Mechanism

We theoretically propose a new stabilization mechanism of a skyrmion crystal (SkX) in a bilayer triangular lattice system consisting of the ferromagnetic and the antiferromagnetic layers. By performing variational calculations and Monte Carlo simulations in a complementary way, we find that a magnetic frustration between the ferromagnetic and antiferromagnetic layers is a source of a finite-Q spiral state and the SkX in the strong interlayer coupling regime. We also show that the degree of frustration is related to the interlayer exchange interaction. The stronger interlayer coupling tends to make the effect of frustration larger, which results in the stabilization of the SkX. The present results not only provide a way of engineering the SkX in the ferromagnetic/antiferromagnetic domain and heterostructure but also imply the possibility of the SkX based on interorbital frustration scenario.

Automated summary

We propose a new stabilization mechanism for a skyrmion crystal (SkX) in a bilayer triangular lattice system. By analyzing the magnetic frustration between the ferromagnetic and antiferromagnetic layers, we find that a finite-Q spiral state and the SkX can be generated in the strong interlayer coupling regime. The degree of frustration is related to the interlayer exchange interaction, and stronger interlayer coupling leads to larger frustration effects and the stabilization of the SkX.