Spontaneous symmetry breaking in a two-dimensional kagome lattice
Spontaneous symmetry breaking in a two-dimensional kagome lattice
We study spontaneous symmetry breakings for fermions (spinless and spinful) on a two-dimensional kagome lattice with nearest-neighbor repulsive interactions in weak coupling limit, and focus in particular on topological Mott insulator instability. It is found that at $\frac{1}{3}$-filling where there is a quadratic band crossing at $\ensuremath{\Gamma}$-point, in agreement with …