Symmetric anisotropic interaction can be ferromagnetic and antiferromagnetic at the same time but for different crystallographic axes. We show that inducing competition of anisotropic interactions of orthogonal irreducible representations represents a general route to obtain new exotic magnetic states. We demonstrate it here by observing the emergence of a continuously tunable 12-layer spatial spin modulation when distorting the square lattice planes in the quasi-2D antiferromagnetic Sr2IrO4 under in situ shear strain. This translation-symmetry-breaking phase is a result of an unusual strain activated anisotropic interaction which is at the 4th order and competing with the inherent quadratic anisotropic interaction. Such a mechanism of competing anisotropy is distinct from that among the ferromagnetic, antiferromagnetic, and/or the Dzyaloshinskii-Moriya interactions, and it could be widely applicable and highly controllable in low dimensional magnets.
@article{arxiv.2204.09176,
title = {Controllable emergent spatial spin modulation in Sr2IrO4 by in situ shear strain},
author = {S. Pandey and H. Zhang and J. Yang and A. F. May and J. Sanchez and Z. Liu and J. -H. Chu and J. W. Kim and P. J. Ryan and H. D. Zhou and J. Liu},
journal= {arXiv preprint arXiv:2204.09176},
year = {2022}
}