Interactions and ultracold collisions between laser-cooled triplet-state He_2 molecules

Objective

Over the last two decades, a drift of interest in molecular science has steered towards the creation and manipulation of ultracold molecules. The intricate internal structure of molecules due to the presence of rotational and vibrational degrees of freedom provide them a special interest for applications in advanced cooling and trapping techniques. To date, only a limited number of studies have investigated the collisional properties of ultracold molecules on the spin-polarized states. This MSCA proposal aims to theoretically explore ultracold molecular interactions and collision dynamics involving metastable noble gas helium molecules in their spin-polarized triplet state (a ³Σ^+_u). The goal is to benchmark He2(a ³Σ)+He(¹S) collisions and to construct high-accuracy four-dimensional (4D) and full six-dimensional (6D) potential energy surfaces (PESs) for high-spin He2(a ³Σ)+He2(a ³Σ) interactions, in order to investigate collision dynamics on these PESs with particular emphasis on rotational deexcitation and vibrational relaxation. These objectives will be accomplished using state-of-the-art ab initio quantum chemistry methods integrated with machine learning approaches, followed by close-coupling scattering calculations. Given that He2 is a light and four-electron system, its PES and scattering properties can be computed with high accuracy. This study will provide a benchmark for interpreting ongoing experimental results and has remain resourceful to stimulate the creation of a molecular Bose-Einstein condensate of He2(a ³Σ) via evaporative cooling. The host institution will provide extensive scientific expertise and support for transferable skills, making it an ideal environment to carry out this project. Additionally, this proposal will significantly enhance researcher’s career prospects by providing new research expertise, international exposure, and management skills essential for pursuing a professorship and contributing to academia with the highest impact.