The response to dynamical modulation of the optical lattice for fermions in the Hubbard model

TL;DR

This paper investigates how time-dependent modulation of an optical lattice affects fermionic atoms in the Hubbard model, revealing significant differences in atomic correlations depending on the system's filling and extending previous static models.

Contribution

It introduces a dynamic treatment of lattice modulation effects using Quantum Monte Carlo and Maximum Entropy, highlighting the importance of time-dependent on-site interactions.

Findings

Modulation effects vary significantly between half-filled and doped regions.

Time-dependent interactions alter atomic correlation results quantitatively.

The study extends static models to include dynamic lattice effects.

Abstract

Fermionic atoms in a periodic optical lattice provide a realization of the single-band Hubbard model. Using Quantum Monte Carlo simulations along with the Maximum Entropy Method, we evaluate the effect of a time-dependent perturbative modulation of the optical lattice amplitude on atomic correlations, revealed in the fraction of doubly-occupied sites. Our treatment extends previous approaches which neglected the time dependence of the on-site interaction, and shows that this term changes the results in a quantitatively significant way. The effect of modulation depends strongly on the filling-- the response of the double occupation is significantly different in the half-filled Mott insulator from the doped Fermi liquid region.