Physical properties of confined fermionic chains in a Wannier-Stark potential

by Prof. Karen Hallberg (Centro Atómico Bariloche and Instituto Balseiro, Bariloche, Argentina)

Tuesday 24 Sept 2024, 11:00 → 12:00 Europe/Zurich

WHGA/121

We study interacting fermions on a finite chain in a Wannier-Stark linear potential using the density matrix renormalization group numerical technique. For the generalized extended Hubbard model, we find that the ground state exhibits a staircase of (quasi) plateaus in the average local site density along the chain, decreasing from being doubly filled to empty as the potential increases. These “plateaus” represent locked-in commensurate phases of charge density waves together with band and Mott insulators. These phases are separated by incompressible regions with incommensurate fillings, as observed from dynamical properties. We suggest that experimental variations of the slope of the potential and the range of the repulsive interactions will produce such a coexistence of phases. We also study the effect of correlations on the localisation length of an extended spinless model with nearest neighbour repulsion and compare with exact analytical results.