High Precision Spectroscopy of Trilobite Rydberg Molecules.

Area of Science:

• Atomic, Molecular, and Optical (AMO) Physics
• Quantum Chemistry
• Spectroscopy

Background:

• High-resolution spectroscopy of ultracold molecules is crucial for testing fundamental theories.
• Previous theoretical models faced convergence issues when calculating molecular properties.
• Ultracold atomic gases provide a unique platform for studying molecular interactions.

Purpose of the Study:

• To obtain high-resolution spectra of Rubidium-87 (⁸⁷Rb) trilobite dimers.
• To provide a rigorous benchmark for existing theoretical models of molecular binding energy.
• To accurately determine low-energy scattering properties of ⁸⁷Rb.

Main Methods:

• Three-photon photoassociation spectroscopy was employed.
• Measurements were performed for principal quantum numbers n=22, 24, 25, 26, and 27.
• A Green's function framework was used for theoretical calculations.

Main Results:

• High-resolution spectra of ⁸⁷Rb dimers were obtained.
• The vibrational spectrum was theoretically reproduced with high accuracy.
• The S-wave electron-atom scattering length was extracted with unprecedented accuracy.

Conclusions:

• The study provides a benchmark for theoretical models using precise molecular binding energy data.
• The Green's function framework successfully addresses previous computational challenges.
• Accurate determination of the scattering phase shift in low-energy regimes was achieved.