Quantum metric and effective mass of a two-body bound state in a flat band
Quantum metric and effective mass of a two-body bound state in a flat band
We consider two-body bound states in a flat band of a multiband system. The existence of pair dispersion predicts the possibility of breaking the degeneracy of the band and creating order, such as superconductivity. Within a separable interaction potential approximation, we find that the finiteness of the effective mass of …