CrCTe$_3$: Computational design of a robust two-dimensional anti-ferromagnetic semiconductor

Using density functional theory calculations we establish the hitherto unknown compound CrCTe$_3$ to be a stable anti-ferromagnetic semiconductor in the R$\bar{3}$ crystal structure with an indirect fundamental gap . Successive layers in the bulk compound are weakly bound by van der Waals forces so that individual layers can be easily exfoliated. A monolayer of CrCTe$_3$ is also an anti-ferromagnetic semiconductor. The monolayer is structurally stable over a large range of compressive and tensile strains, and the anti-ferromagnetic state is robust over this strain range. Band gap of the monolayer can be tuned by as much as 50% by applying strain in this range.