The Mottness is at the heart of the essential physics in a strongly
correlated system as many novel quantum phenomena occur at the metallic phase
near the Mott metal-insulator transition. We investigate the Mott
metal-insulator transition in a strongly-correlated electron system based on
the Hubbard model. The on-site moment evaluated by the dynamical mean-field
theory is employed to depict the Mott metal-insulator transition. Conveniently,
the on-site moment is a more proper order parameter to quantitatively determine
the Mott critical point, in comparison with the corresponding quasiparticle
coherent weight. Moreover, this order parameter also gives a consistent
description of two distinct forms of the critical points of the Mott
metal-insulator transition.Comment: 6 pages, 4 figure