Ultracold Li + Li2 collisions: bosonic and fermionic cases

Area of Science:

• Atomic and Molecular Physics
• Quantum Dynamics
• Quantum Chemistry

Background:

• Vibrational quenching is crucial for understanding energy transfer in atomic and molecular collisions.
• Previous studies have explored these processes, but calculations involving fermionic atoms were lacking.

Purpose of the Study:

• To perform quantum dynamical calculations for vibrational quenching in lithium atom (Li) and diatomic lithium molecule (Li2) collisions.
• To investigate the role of atomic statistics (bosonic vs. fermionic) in these collision dynamics.
• To compare results for low vibrational states with existing experimental data for high vibrational states.

Main Methods:

• Utilized quantum dynamical calculations to simulate Li + Li2 collisions.
• Specifically calculated cross-sections and rate coefficients for vibrational transitions.
• Employed methods suitable for handling both bosonic (7Li) and fermionic (6Li) isotopes.

Main Results:

• Calculated vibrational quenching rates for low initial states (v ≤ 3) of Li2 in collisions with both 7Li and 6Li.
• Found no significant suppression of quenching rates for fermionic 6Li compared to bosonic 7Li.
• Observed a discrepancy between these low-vibrational state calculations and experimental findings for high-vibrational states involving Feshbach resonances.

Conclusions:

• Atomic statistics do not suppress vibrational quenching rates in Li + Li2 collisions at low initial vibrational states.
• The behavior of vibrational quenching differs between low and very high vibrational states.
• These results highlight the importance of considering the specific collision regime and atomic properties in quantum dynamics.