Electronic properties, correlated topology and Green's function zeros

There is extensive current interest about electronic topology in correlated settings, and this

motivates the consideration of topological invariants and experimentally observable electronic

properties based on Green’s functions. In a Mott insulator, contours of Green’s function zeros

may develop within its correlated gap. However, further investigation is needed to determine

whether and how the contour of zeros contributes to observable quantities. In this work, we

systematically studied the relationship between the Green’s functions and two physical

observable quantities: the total electron number and the Hall conductivity. By studying an

exactly solvable Mott insulator model, we demonstrate that the Green’s function zeros and poles

contribute to these observable quantities in a way that the physical properties remain robust to

chemical potential variations up to the Mott gap at zero temperature as it should be without

running into inconsistencies. Our result provides new prospective for the interplay among

topology, symmetry and strong correlation.