Rydberg trimers and excited dimers bound by internal quantum reflection

Area of Science:

• Atomic, Molecular, and Optical Physics
• Quantum Chemistry
• Condensed Matter Physics

Background:

• Ultracold long-range Rydberg molecules are exotic states of matter with unique quantum properties.
• Understanding their formation and binding mechanisms is crucial for exploring novel quantum phenomena.
• Previous research has explored various types of Rydberg molecules, but new formation pathways and binding mechanisms remain areas of active investigation.

Purpose of the Study:

• To report on the creation and characterization of two novel types of ultracold long-range Rydberg molecules.
• To demonstrate a single-step photoassociation technique for creating triatomic Rydberg molecules.
• To identify and explain a new binding mechanism for excited dimer states based on internal quantum reflection.

Main Methods:

• Combined experimental and theoretical approaches were employed.
• Single-step photoassociation was used to create triatomic molecules (one Rydberg atom and two ground-state atoms).
• Spectroscopic analysis and theoretical modeling were used to assign excited dimer states and elucidate their binding mechanism.

Main Results:

• Demonstrated the creation of triatomic Rydberg molecules in a single step.
• Identified excited dimer states bound by a novel mechanism involving internal quantum reflection at a steep potential drop.
• Characterized the properties of these novel Rydberg molecules.

Conclusions:

• The identified Rydberg molecules are prototypes for a new regime of chemistry at ultracold temperatures.
• The novel binding mechanism expands the understanding of molecular interactions in Rydberg systems.
• This work opens new avenues for the creation and application of ultracold molecules.