Spectroscopic detection of the LiHe molecule.

Area of Science:

• Atomic, Molecular, and Chemical Physics
• Quantum Chemistry
• Thermodynamics

Background:

• Formation of weakly bound molecules is crucial for ultracold chemistry.
• Lithium-helium (LiHe) molecules are van der Waals complexes with unique properties.
• Previous methods for creating LiHe molecules had limitations in density and control.

Purpose of the Study:

• To develop a novel method for producing high densities of LiHe molecules.
• To spectroscopically detect and characterize these LiHe molecules.
• To experimentally determine the binding energy of LiHe molecules from thermodynamic data.

Main Methods:

• Utilizing cryogenic helium buffer-gas cooling to achieve low temperatures.
• Inducing three-body recombination of lithium atoms in a dense helium gas environment.
• Employing spectroscopic techniques for molecule detection and characterization.
• Measuring equilibrium thermodynamic properties to infer binding energy.

Main Results:

• Successfully formed large densities of lithium atoms and LiHe molecules.
• Spectroscopic evidence confirmed the presence of LiHe molecules.
• Experimentally determined the binding energy of the LiHe van der Waals molecules.

Conclusions:

• Cryogenic buffer-gas cooling is an effective technique for creating dense ultracold molecular gases.
• The study provides crucial experimental data on the binding energy of LiHe molecules.
• This work opens avenues for further investigations into ultracold van der Waals systems.