Exploring and controlling magnetism in two-dimensional (2D) layered magnetic crystals, as well as their inclusion in heterogeneous assemblies, provide an unprecedented opportunity for fundamental science and technology. To date, however, there are only a few known intrinsic 2D magnets. Here we predict a novel 2D intrinsic magnet, yttrium sulfur selenide (YSSe), using first-principles calculations. The magnetism of this transition metal dichalcogenide originates from the partially-filled 3p- and 4p-orbitals of the chalcogens, unlike other known intrinsic magnets where magnetism arises from the partially-filled 3d- and 4f-orbitals. The unconventional magnetism in YSSe is a result of a unique combination of its structural and electronic properties. We further show that a lack of mirror symmetry results in piezoelectric properties, while the broken space- and time-symmetry ensures valley polarization. YSSe is a rare magnetic-piezoelectric material that can enable novel spintronics, valleytronics, and quantum technologies.
@article{arxiv.2009.07232,
title = {A new class of intrinsic magnet: two-dimensional yttrium sulphur selenide},
author = {Pankaj Kumar and Ivan I. Naumov and Priyanka Manchanda and Pratibha Dev},
journal= {arXiv preprint arXiv:2009.07232},
year = {2020}
}