In the framework of mean field approach, we study topological Mott transition in a two band model of spinless fermions on a square lattice at half filling. We consider the combined effects of the on-site Coulomb repulsion and the spin-orbit Rashba coupling. The spin-orbit Rashba coupling leads to a distinct phase of matter, the topological semimetal. We are talking about a new type of phase transition between the non-topological insulator state and topological semimetal state. New phase state is characterized by the zero energy Majorana states, which there are in defined region of the wave vectors and are localized at the boundaries of the sample. The zero energy Majorana states are dispersionless (they can be considered as flat bands), the Chern number and Hall conductance are equal to zero (note in two dimensional model).(note in two dimensional model).
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