Shedding Light on Three-Body Recombination in an Ultracold Atomic Gas

TL;DR

This study introduces a novel sensitive detection method to analyze the molecular quantum states produced by three-body recombination in ultracold gases, revealing broad state populations and advancing understanding of this complex process.

Contribution

The paper presents the first experimental approach to measure the population distribution of molecular states after three-body recombination in ultracold gases.

Findings

Identified population of energy levels up to 750 GHz binding energy

Observed broad distribution of electronic and nuclear spin states

Mapped vibrational and rotational state populations

Abstract

Three-body recombination is a prime example of the fundamental interaction between three particles. Due to the complexity of this process it has resisted a comprehensive description. Experimental investigations have mainly focussed on the observation of corresponding loss rates without revealing information on the reaction products. Here, we provide the first general experimental study on the population distribution of molecular quantum states after three-body recombination in a non-resonant regime. We have developed a highly sensitive detection scheme which combines photoionization of the molecules with subsequent ion trapping. By analyzing the ionization spectrum, we identify the population of energy levels with binding energies up to $h\times 750\:$GHz. We find a broad population of electronic and nuclear spin states and determine a range of populated vibrational and rotational states. The method presented here can be expanded to provide a full survey of the products of the recombination process. This may be pivotal in developing an in-depth model that can qualitatively and quantitatively predict the reaction products of three-body recombination.