Dynamics of fermions in an amplitude modulated lattice

TL;DR

This paper analyzes the dynamics of fermions in an amplitude-modulated optical lattice, improving semiclassical models to better match experimental observations, including phenomena like collapse and revival of holes.

Contribution

It provides a more detailed semiclassical analysis considering dimensionality and temperature, enhancing the accuracy of modeling fermionic dynamics in optical lattices.

Findings

Semiclassical dynamics match experimental data more accurately.

Collapse and revival phenomena of holes are characterized in detail.

Finite temperature effects are incorporated into the model.

Abstract

We study dynamics of fermions loaded in an optical lattice with a superimposed parabolic trap potential. In the recent Hamburg experiments [J.Heinze et.al., Phys. Rev. Lett. 110, 085302 (2013)] on quantum simulation of photoconductivity, a modulation pulse on the optical lattice transferred part of the population of the lowest band to an excited band, leaving a hole in the particle distribution of the lowest band. Subsequent intricate dynamics of both excited particles and holes can be explained by a semiclassical approach based on the evolution of Wigner function. Here we provide a more detailed analysis of the dynamics taking into account the dimensionality of the system and finite temperature effects, aiming at reproducing experimental results on longer timescales. A semiclassical wave packet is constructed more accurately than in the previous theory. As a result, semiclassical dynamics indeed reproduces experimental data and full quantum numerical calculations with much better accuracy. In particular, fascinating phenomenon of collapse and revival of holes is investigated in a more detail. We presume the experimental setup can be used for deeper exploration of nonlinear waves in fermionic gases.