Field-linked resonances of polar molecules

Area of Science:

• Atomic and Molecular Physics
• Quantum Gases
• Ultracold Molecules

Background:

• Scattering resonances are crucial for controlling ultracold atom and molecule interactions.
• Conventional Feshbach resonances are limited in polar molecules due to rapid loss at close distances.
• A new approach is needed for controlled interactions in ultracold polar molecular systems.

Purpose of the Study:

• To demonstrate a new, universal type of scattering resonance for polar molecules.
• To investigate field-linked resonances in microwave-dressed ultracold molecules.
• To control inelastic collision rates and interactions in sodium-potassium molecules.

Main Methods:

• Utilized microwave dressing to create field-linked resonances in ultracold polar molecules.
• Identified and studied two resonances in ultracold ground-state sodium-potassium molecules.
• Tuned collision rates by three orders of magnitude using microwave frequencies and polarizations.

Main Results:

• Demonstrated field-linked resonances, a universal phenomenon for polar molecules.
• Achieved independent control over elastic contact and dipole-dipole interactions.
• Observed modifications in thermalization rates due to controlled interactions.

Conclusions:

• Field-linked resonances offer a general strategy for controlling ultracold polar molecule scattering.
• This technique enables independent tuning of interaction types, crucial for quantum simulations.
• Paves the way for realizing dipolar superfluids, molecular supersolids, and assembling polyatomic molecules.