Electric-Field-Controlled Cold Dipolar Collisions between Trapped CH_{3}F Molecules.

Area of Science:

• Atomic, Molecular, and Optical Physics
• Quantum Chemistry
• Chemical Physics

Background:

• High phase-space density is essential for studying cold-collision phenomena in polyatomic molecules.
• Previous methods struggled to achieve the necessary densities for advanced molecular experiments.

Purpose of the Study:

• To develop and demonstrate a technique for reaching high densities of polyatomic molecules for cold-collision studies.
• To investigate the control of inelastic collision rates in a dense molecular sample.

Main Methods:

• Utilized a cryofuge to load methyl fluoride (CH3F) molecules into a boxlike electric trap.
• Achieved densities up to 10^7 molecules/cm^3 at temperatures around 350 mK.
• Employed a homogeneous electric field to control inelastic collision rates.

Main Results:

• Reached densities of 2x10^7 CH3F molecules, exceeding 10^7/cm^3.
• Measured elastic dipolar cross sections greater than 7x10^-12 cm^2.
• Observed inelastic rate constants below 4x10^-8 cm^3/s, tunable via electric field.

Conclusions:

• The developed technique successfully achieves high molecular densities for cold-collision experiments.
• Dipolar relaxation rates show excellent agreement with ab initio calculations.
• The methods are broadly applicable to other cold-molecule collision research.