Strain-induced manipulation of noncollinear antiferromagnets

Recently, interest has grown in harnessing noncollinear antiferromagnets (NCAFMs) for applications in antiferromagnetic spintronics. A key requirement for their practical use is the ability to control the spin order in a reliable and tunable manner. We investigate how the spin order in kagome antiferromagnets—an important class of NCAFMs—can be manipulated via strain. Starting from a microscopic spin Hamiltonian, we derive an effective action that captures the coupling between the spin order and the system's strain tensor. Microscopically, this coupling arises from strain-induced modifications of the Dzyaloshinskii-Moriya and exchange interactions. Using this effective description, we explore two strain-driven phenomena: (1) the piezomagnetic response and (2) strain-induced switching of the antiferromagnetic spin order. We show that strain linearly induces a net magnetization and provide an experimentally testable prediction in Mn₃Sn. Moreover, we numerically show that strain can facilitate thermally assisted chirality switching of the spin order. In particular, we find that strain governs both the average switching time and direction between chiral states. Our results provide a general theoretical framework for modeling strain-induced manipulations of kagome antiferromagnets, underscoring strain as a promising route for functional control of NCAFMs in antiferromagnetic spintronic devices.