14 - Two-dimensional magnetism in Xenes

Abstract

Magnetism is emerging as a key property of two-dimensional (2D) materials and heterostructures. 2D magnetism engenders new quantum and topological phases, endows materials with unexpected functionalities, and inspires new device concepts. The family of Xenes and their derivatives—materials at the core of 2D research—present an important constituent to the library of 2D magnets. Here, we trace out the development of Xene magnetism from general theoretical guidelines to experimental realization of intrinsic 2D magnets in a class of Xene compounds. In particular, we review the synthesis and properties of silicene and germanene coupled with rare earths which evolve from antiferromagnets in multilayer structures to 2D ferromagnets in the monolayer (ML) limit. Unconventional transport properties accompany magnetism in Xene materials to exhibit high carrier mobility in multilayers, colossal exponential negative magnetoresistance in one ML, and layer-controlled laws of electron transport. Furthermore, we demonstrate that the general approach developed for Xenes is applicable to graphene, making it ferromagnetic. Finally, we outline the potential future developments in Xene magnetism.