State selective preparation and nondestructive detection of trapped O2

Area of Science:

• Atomic and Molecular Physics
• Quantum Information Science
• Spectroscopy

Background:

• Preparing molecular ions in specific quantum states is crucial for advanced research.
• Resonance-enhanced multiphoton ionization (REMPI) is a key technique for this purpose.
• Oxygen (O2) is a fundamental molecule with applications across various scientific disciplines.

Purpose of the Study:

• To demonstrate state-selective ionization of oxygen molecules using (2 + 1) REMPI.
• To resolve discrepancies in the spectroscopic parameters of the O2 d 1Πg state.
• To explore applications in quantum information and precision measurements.

Main Methods:

• Utilizing (2 + 1) resonance-enhanced multiphoton ionization (REMPI) on oxygen in a molecular beam and ion trap.
• Achieving rotationally resolved REMPI spectra for state selection.
• Employing co-trapped atomic ions for cooling molecular ions and fluorescence mass spectrometry for detection.

Main Results:

• Successfully ionized oxygen molecules from selected rovibrational states.
• Determined precise spectroscopic parameters for the O2 d 1Πg state, resolving a literature discrepancy.
• Demonstrated nondestructive detection of trapped O2+ ions via fluorescence mass spectrometry.
• Identified optimal REMPI transitions (Q(1) vs. O(3)) for different rotational temperatures.

Conclusions:

• State-selective preparation and detection of molecular ions are achievable with (2 + 1) REMPI.
• This technique provides a pathway for high-precision spectroscopy and quantum control of molecules.
• Applications include optical clocks, fundamental physics tests, and controlled chemical reactions.