SrRuO$_3$ heterostructures grown in the (111) direction are a rare example of thin film ferromagnets. By means of density functional theory plus dynamical mean field theory we show that the half-metallic ferromagnetic state with an ordered magnetic moment of 2$\mu_{ B}$/Ru survives the ultimate dimensional confinement down to a bilayer, even at elevated temperatures of 500$\,$K. In the minority channel, the spin-orbit coupling opens a gap at the linear band crossing corresponding to $\frac34$ filling of the $t_{ 2g}$ shell. We demonstrate that the respective state is Haldane's quantum anomalous Hall state with Chern number $C$=1, without an external magnetic field or magnetic impurities.
Categories: cond-mat.str-el