Flat band induced room-temperature ferromagnetism in two-dimensional systems
G. Bouzerar
Abstract
The remarkable and fascinating properties of two-dimensional (2D) materials have raised them to the rank of most promising candidates for technological applications. In particular, the possibility of long-range ferromagnetic order in 2D materials is generating a growing excitement. Here, we demonstrate that flat bands (FBs) can pave the way for room-temperature ferromagnetism in 2D compounds. Indeed, the magnetic exchanges between localized spins are largely dominated by the FB-FB contribution. This contribution is ferromagnetic and scales linearly with the local coupling, thus leading to crossover temperatures (ferromagnetic phase/paramagnetic phase) higher by an order of magnitude than those currently reported in experiments. High crossover temperatures could be reached in micrometer-sized FB systems.