Dipolar Dynamics for Interacting Ultracold Fermions in a Trapped Optical Lattice

TL;DR

This paper uses numerical simulations to study how ultracold interacting fermions in an optical lattice respond dynamically to trap displacements, revealing different behaviors for attractive and repulsive interactions and predicting a revival of oscillations linked to Mott physics.

Contribution

It introduces a detailed numerical analysis of dipolar dynamics in trapped Fermi gases, highlighting new dynamical signatures of Mott plateau formation.

Findings

Attractive interactions lead to underdamped oscillations and overdamped relaxations.

Repulsive interactions cause a predicted revival of center-of-mass oscillations.

Numerical results align with experimental observations.

Abstract

Using the time-dependent density matrix renormalization group method, we calculate transport properties of an interacting Fermi gas in an optical lattice with a confining trap after a sudden displacement of the trap center. In the regime of attractive interactions, the dipolar motion after the displacement can be classified into underdamped oscillations and overdamped relaxations, depending on the interaction strength. These numerical calculations are consistent with experimental results. In the regime of repulsive interactions, we predict a revival of the oscillations of the center of mass when the interaction strength is increased. This unique feature can be considered as a dynamical signature for the emergence of a Mott plateau for an interacting trapped Fermi gas in an optical lattice.