Magnetism in 2D flatland: understanding from ab initio theory

Since the discovery of graphene, an enormous attention has been paid to
explore new two-dimensional (2D) materials with novel functionalities.
The latest addition is the realization of magnetic long range order in
atomically thin 2D materials, which has a big potential due to the
manipulation of magnetism by external fields, strain or creating
heterostructures. In this talk, I will review the status of this
research field, highlighting our own research on (i) dependence
of stacking sequence on magnetism in CrI3 multilayers,
(ii) complex magnetism in 2D FeS2, (iii) structural reconstruction
and peculiar magnetism in 2D Fe5GeTe2. I will also highlight the
importance of electron correlation and spin-orbit coupling. All
these results have been obtained by ab initio density functional
theory, calculations of interatomic exchange interaction parameters
and Monte Carlo simulations.