High-field magnetic phase diagrams of the $\textit{R}$Mn$_6$Sn$_6$ kagome metals

Abstract

$\textit{R}$Mn$_6$Sn$_6$ ($R=$~Y,~Gd$-$Lu) kagome metals are promising materials hosting flat electronic bands and Dirac points that interact with magnetism. The coupling between the two magnetic $R$ and Mn sublattices can drive complex magnetic states with potential consequences for spin and charge transport and other topological properties. Here, we use a detailed magnetic Hamiltonian to calculate and predict the magnetic phase diagrams for $\textit{R}$Mn$_6$Sn$_6$ kagome metals within the mean-field approximation. These calculations reveal a variety of collinear, non-collinear, and non-coplanar phases that arise from competition between various interlayer magnetic exchange interactions and magnetic anisotropies of the $R$ and Mn ions. We enumerate these phases and their magnetic space groups for future analysis of their impact on topological and trivial bands near the Fermi surface.