  We present a numerical study of the SU(3) Heisenberg model of three-flavor
fermions on the triangular and square lattice by means of the density-matrix
renormalization group (DMRG) and infinite projected entangled-pair states
(iPEPS). For the triangular lattice we confirm that the ground state has a
three-sublattice order with a finite ordered moment which is compatible with
the result from linear flavor wave theory (LFWT). The same type of order has
recently been predicted also for the square lattice [PRL 105, 265301 (2010)]
from LFWT and exact diagonalization. However, for this case the ordered moment
cannot be computed based on LFWT due to divergent fluctuations. Our numerical
study clearly supports this three-sublattice order, with an ordered moment of
m=0.2-0.4 in the thermodynamic limit.
