Magnetic competition with different spin chiralities in kagome magnets

Abstract

Using the Bogoliubov variational method we study the magnetic competition in a minimal model proposed for kagome magnets. The minimal model consists of itinerant electrons with their spin-orbit coupling and localized electrons with their anisotropic spin exchange. A spin exchange between localized and itinerant electrons is also included into the model, and it is anisotropic. At half filling and in the region of stable in-plane antiferromagnetism, a magnetic competition between antiferromagnetic phases with different spin chiralities is found. Depending on the sign of the hopping integral and the spin-orbit coupling, either the 1 × 1 or 3 × 3 in-plane antiferromagnetism is established. These in-plane antiferromagnetic states are characterized by distinguishable spin chiralities.