Exploring Unconventional Hubbard Models with Doubly Modulated Lattice Gases

TL;DR

This paper demonstrates how double modulation of optical lattices enables the engineering of diverse Hubbard models with unique phases and regimes, advancing quantum simulation capabilities.

Contribution

It introduces a novel double modulation technique combining lattice shaking and interaction modulation to realize complex Hubbard models with correlated hopping.

Findings

Double modulation enables asymmetric hopping in Hubbard models.

Insulating phases with parity and string order are achievable.

Simulation of unconventional parameter regimes for cuprate models is possible.

Abstract

Recent experiments show that periodic modulations of cold atoms in optical lattices may be used to engineer and explore interesting models. We show that double modulation, combining lattice shaking and modulated interactions allows for the engineering of a much broader class of lattice models with correlated hopping, which we study for the particular case of one-dimensional systems. We show, in particular, that by using this double modulation it is possible to study Hubbard models with asymmetric hopping, which, contrary to the standard Hubbard model, present insulating phases with both parity and string order. Moreover, double modulation allows for the simulation of lattice models in unconventional parameter regimes, as we illustrate for the case of the spin-$1/2$ Fermi-Hubbard model with correlated hopping, a relevant model for cuprate superconductors.