Test of Particle-Assisted Tunneling for Strongly Interacting Fermions in an Optical Superlattice

TL;DR

This paper proposes an experimental scheme using ultracold atoms in an optical superlattice to test the particle-assisted tunneling predictions of the effective Hubbard model for strongly interacting fermions.

Contribution

It introduces a method to experimentally verify the particle-assisted tunneling rates and low-energy Hilbert space structure predicted by the effective Hamiltonian.

Findings

Measurement of time-of-flight images reveals tunneling rates.

Structure of low-energy Hilbert space can be inferred.

Experimental validation of the effective Hubbard model.

Abstract

Fermions in an optical lattice near a wide Feshbach resonance are expected to be described by an effective Hamiltonian of the general Hubbard model with particle-assisted tunneling rates resulting from the strong atomic interaction [Phys. Rev. Lett. 95, 243202 (2005)]. Here, we propose a scheme to unambiguously test the predictions of this effective Hamiltonian through manipulation of ultracold atoms in an inhomogeneous optical superlattice. The structure of the low-energy Hilbert space as well as the particle assisted tunneling rates can be inferred from measurements of the time-of-flight images.