As part of my Marie-Curie Action TEBLa, I explore the superfluid properties of a many-body bosonic system on a lattice in connection with the many-body quantum geometric tensor.

Together with Tomoki Ozawa from Tohoku University, we study the effect of quantum geometry on the many-body ground state of one-dimensional interacting bosonic systems. We find that the Drude weight is given by the sum of the kinetic energy and a term proportional to the many-body quantum metric of the ground state. Notably, the many-body quantum metric determines the upper bound of the Drude weight. We validate our results on the Creutz ladder, a flat band model, using exact diagonalization at half and unit densities. Our work sheds light on the importance of the many-body quantum geometry in one-dimensional interacting bosonic systems.

Read our Letter on Physical Review B