Breakdown of the Luttinger sum rule within the Mott-Hubbard insulator

The validity of the Luttinger sum rule is investigated within the prototype tight-binding model of interacting fermions in one dimension, i.e., the t-V model including the next-nearest-neighbor hopping t('), in order to break the particle-hole symmetry. Scaling analysis of finite-system results at half filling reveals evident breakdown of the sum rule in the large gap regime at V > t while the sum rule appears to recover together with vanishing of the Mott-Hubbard gap.