Altermagnetism exhibits advantages over both ferromagnetic and antiferromagnetic counterparts by enabling spin splitting within antiferromagnetic materials. Currently, it is established that valley polarization in altermagnetism remains largely insensitive to spin-orbit coupling and spin. Here, using Cr2S2 as a case study, we investigate the mechanism through which an external field modulates valley polarization in altermagnetism. This effect arises from the external field's disruption of diagonal mirror symmetry Mxy, consequently inducing valley polarization within the material. Strain not only induces valley polarization but also generates an almost uniform magnetic field, which can reach as high as 118.39 T under 5% uniaxial strain. In addition, this symmetry breaking in Cr2S2 monolayers results in significant piezomagnetic properties, merging piezomagnetic and altermagnetic characteristics in two-dimensional materials.
@article{arxiv.2410.17686,
title = {Strain-modulated Valley Polarization and Piezomagnetic Effects in Altermagnetic Cr$_2$S$_2$},
author = {Chen Chen and Xiaoyang He and Qizhen Xiong and Chuye Quan and Haojie Hou and Shilei Ji and Jianping Yang and Xing'ao Li},
journal= {arXiv preprint arXiv:2410.17686},
year = {2024}
}