  Metal-insulator transitions are studied within a three-component
Falicov-Kimball model which mimics a mixture of one-component and two-component
fermionic particles with local repulsive interactions in optical lattices.
Within the model the two-component fermionic particles are able to hop in the
lattice, while the one-component fermionic particles are localized. The model
is studied by using the dynamical mean-field theory with exact diagonalization.
Its homogeneous solutions establish Mott transitions for both commensurate and
incommensurate fillings between one third and two thirds. At commensurate one
third and two thirds fillings the Mott transition occurs for any density of
hopping particles, while at incommensurate fillings the Mott transition can
occur only for density one half of hopping particles. At half filling,
depending on the repulsive interactions the reentrant effect of the Mott
insulator is observed. As increasing local interaction of hopping particles,
the first insulator-metal transition is continuous, whereas the second
metal-insulator transition is discontinuous. The second metal-insulator
transition crosses a finite region where both metallic and insulating phase
coexist. At third filling the Mott transition is established only for strong
repulsive interactions. A phase separation occurs together with the phase
transition.
