Electrostatic Trapping of N_{2} Molecules in High Rydberg States.

Area of Science:

• Physical Chemistry
• Atomic and Molecular Physics
• Quantum Mechanics

Background:

• Nitrogen molecules (N_{2}) possess complex electronic structures, enabling excitation to various states.
• Rydberg states are highly excited electronic states characterized by large principal quantum numbers.
• Trapping neutral molecules with electric fields requires specific molecular properties like large dipole moments.

Purpose of the Study:

• To excite nitrogen molecules to high-principal-quantum-number Rydberg states.
• To investigate the possibility of decelerating and trapping these excited molecules using electric fields.
• To understand the decay dynamics and mechanisms of trapped Rydberg nitrogen molecules.

Main Methods:

• Utilized a resonance-enhanced two-color three-photon excitation scheme to populate N_{2} Rydberg states (n=39-48).
• Employed inhomogeneous electric fields to decelerate excited N_{2} molecules to rest and achieve 3D trapping.
• Measured trap decay time constants and analyzed decay dynamics in comparison to helium atom studies.

Main Results:

• Successfully populated N_{2} Rydberg states with large static electric dipole moments (>5000 D).
• Achieved deceleration and 3D trapping of Rydberg N_{2} molecules, with confinement up to 10 ms.
• Observed trap decay time constants ranging from 450 to 700 μs, increasing with principal quantum number.

Conclusions:

• The large dipole moments of the populated Rydberg states are key for electric field manipulation.
• Spontaneous emission is the dominant decay mechanism for trapped Rydberg N_{2} molecules.
• Intramolecular interactions leading to non-radiative decay appear to be insignificant in this system.