Photoassociation and coherent transient dynamics in the interaction of ultracold rubidium atoms with shaped femtosecond pulses - II. Theory

TL;DR

This paper presents a theoretical study of ultracold rubidium atom photoassociation using shaped femtosecond pulses, focusing on how spectral cutoff and chirp influence coherent transient dynamics and molecule formation.

Contribution

It introduces a theoretical model analyzing the effects of spectral cutoff and pulse chirp on photoassociation and coherent transients in ultracold rubidium atoms.

Findings

Spectral cutoff suppresses near-resonance amplitudes, leading to long pulse tails.

Coherent transients depend on cutoff position and chirp.

Molecule formation occurs via off-resonant excitation in strong fields.

Abstract

Photoassociation of ultracold rubidium atoms with femtosecond laser pulses is studied theoretically. The spectrum of the pulses is cut off in order to suppress pulse amplitude at and close to the atomic resonance frequency. This leads to long tails of the laser pulse as a function of time giving rise to coherent transients in the photoassociation dynamics. They are studied as a function of cutoff position and chirp of the pulse. Molecule formation in the electronically excited state is attributed to off-resonant excitation in the strong-field regime.