Interfacial Dzyaloshinskii-Moriya interaction in nonmagnetic/noncollinear-antiferromagnetic bilayers

Abstract: We study Dzyaloshinskii-Moriya interaction (DMI) appearing at the interface of a nonmagnetic/noncollinear-antiferromagnetic bilayer. DMI is an antisymmetric exchange interaction between neighboring magnetic spins, arising in the absence of inversion center between the spins and the explicit expression of which being dictated by system symmetry. We formulate the interfacial DMI for different crystalline orientations of the noncollinear antiferromagnet with stacked-Kagome lattice structure. From this formulation, we show that, when the Kagome planes are perpendicular to the sample film plane, the DMI serves as a uniaxial magnetic anisotropy for the antiferromagnetic order parameter. Our findings reveal a novel physical manifestation of a DMI, shedding a new light on microscopic mechanisms of the magnetic anisotropy in noncollinear antiferromagnets.