Resonant collisional shielding of reactive molecules using electric fields

Area of Science:

• Quantum Science
• Ultracold Molecules
• Chemical Reaction Dynamics

Background:

• Controlling molecular interactions is crucial for advancing quantum science.
• Reactive losses in molecular samples limit experimental timescales and precision.
• Existing methods offer limited tunability of chemical reaction rates.

Purpose of the Study:

• To demonstrate extreme tunability of ultracold chemical reaction rates.
• To investigate the role of resonant dipolar interactions in controlling molecular collisions.
• To realize a long-lived sample of polar molecules in strong electric fields.

Main Methods:

• Preparation of fermionic potassium-rubidium molecules in their first excited rotational state.
• Application of an external electric field to induce resonant dipolar interactions.
• Measurement of chemical reaction rates in a quasi-two-dimensional geometry.
• Analysis of collision contributions from dominant angular momentum projections.

Main Results:

• Observed a three-orders-of-magnitude modulation of chemical reaction rates by tuning electric field strength across resonance.
• Accurately determined contributions from three dominant angular momentum projections.
• Suppressed reaction rates by an order of magnitude below background using resonant features.

Conclusions:

• Extreme tunability of ultracold chemical reaction rates is achievable via resonant dipolar interactions.
• Electric field control enables shielding of molecules from reactive loss.
• Realized a long-lived sample of polar molecules, opening new frontiers in quantum science.