A new class of intrinsic magnet: two-dimensional yttrium sulphur selenide

TL;DR

This paper predicts a new 2D intrinsic magnet, yttrium sulfur selenide (YSSe), which exhibits unique magnetic, piezoelectric, and valley polarization properties, opening avenues for advanced quantum and spintronic applications.

Contribution

The study introduces YSSe as a novel 2D intrinsic magnet with unconventional magnetism from chalcogen orbitals, expanding the class of 2D magnetic materials.

Findings

YSSe exhibits intrinsic magnetism from chalcogen orbitals.

YSSe shows piezoelectric properties due to lack of mirror symmetry.

YSSe enables potential applications in spintronics and valleytronics.

Abstract

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.