Coupling of Electronic and Motional Dynamics in a Cold Atom Optical Lattice

TL;DR

This paper investigates how electronic excitations in ultracold atoms within an optical lattice couple to vibrational modes, affecting transition energies and causing motional heating through dipole-dipole interactions.

Contribution

It introduces a detailed analysis of the coupling mechanisms between electronic and motional states, including effects on transition energies and vibrational excitation processes.

Findings

On-site coupling renormalizes electronic transition energies.

Dipole-dipole interactions induce vibrational excitation and heating.

Perturbation estimates quantify the coupling parameters.

Abstract

We study the coupling of internal electronic excitations to vibrational modes of the external motion of ultracold atoms in an optical lattice. For different ground and excited state potentials the on-site coupling of excitations and vibrations term renormalizes the effective electronic transition energy, which appears e.g. in clock transitions. In addition in the Mott state with filling factor one, the dipole-dipole coupling between neighbouring sites includes emission and absorption of vibrational quanta. Such processes create a significant mechanism for excitation of vibrations leading to motional heating of the lattice atoms by resonant light interaction. We calculate estimates of the corresponding parameters from a perturbation expansion in small atomic displacements.