Bimodal momentum distribution of the high-density supersolid state

By performing exact quantum Monte Carlo simulations, we study the momentum distribution of the supersolid state in the two-dimensional extended Bose- Hubbard model with the nearest-neighbor repulsion. For strong nearest-neighbor repulsions, the supersolid state is stable in a broad region up to large hopping amplitudes and high particle densities. In the supersolid state, the momentum distribution shows a bimodal structure with two peaks related to the superfluidity and solidity respectively. By our calculations, we show that the bimodal structure becomes clearer as the chemical potential (or the particle density) is increased.