Engineering an all-optical route to ultracold molecules in their vibronic ground state

TL;DR

This paper introduces an all-optical method using short laser pulses and an auxiliary laser field to efficiently produce ultracold molecules in their vibronic ground state, overcoming non-adiabatic transfer challenges.

Contribution

It presents a novel photoassociation scheme employing a Raman-like pump-dump process with an auxiliary laser to enhance ground state molecule formation.

Findings

Efficient transfer to low-lying vibrational levels achieved.

Repetitive sequences and collisional relaxation enable accumulation in v=0.

Method applicable without non-adiabatic effects.

Abstract

We propose an improved photoassociation scheme to produce ultracold molecules in their vibronic ground state for the generic case where non-adiabatic effects facilitating transfer to deeply bound levels are absent. Formation of molecules is achieved by short laser pulses in a Raman-like pump-dump process where an additional near-infrared laser field couples the excited state to an auxiliary state. The coupling due to the additional field effectively changes the shape of the excited state potential and allows for efficient population transfer to low-lying vibrational levels of the electronic ground state. Repetition of many pump-dump sequences together with collisional relaxation allows for accumulation of molecules in v=0.