State Selective Preparation and Nondestructive Detection of Trapped ${\mathrm{O}}_2^{+}$

Abstract

The ability to prepare molecular ions in selected quantum states enables studies in areas such as chemistry, metrology, spectroscopy, quantum information, and precision measurements. Here, we demonstrate $(2+1)$ resonance-enhanced multiphoton ionization (REMPI) of oxygen, both in a molecular beam and in an ion trap. The two-photon transition in the REMPI spectrum is rotationally resolved, allowing ionization from a selected rovibrational state of O${}_2$. Fits to this spectrum determine spectroscopic parameters of the O${}_2$ $d{}^1{\Pi }_g$ state and resolve a discrepancy in the literature regarding its band origin. The trapped molecular ions are cooled by co-trapped atomic ions. Fluorescence mass spectrometry nondestructively demonstrates the presence of the photoionized O${}_2^{+}$. We discuss strategies for maximizing the fraction of ions produced in the ground rovibrational state. For $(2+1)$ REMPI through the $d{}^1{\Pi }_g$ state, we show that the Q(1) transition is preferred for neutral O${}_2$ at rotational temperatures below 50~K, while the O(3) transition is more suitable at higher temperatures. The combination of state-selective loading and nondestructive detection of trapped molecular ions has applications in optical clocks, tests of fundamental physics, and control of chemical reactions.

Authors Accepted Manuscript. 10 pages, 6 figures, 3 tables

References in corpus (10)

• A new bound on the electron's electric dipole moment
• Proton-Electron Mass Ratio from Laser Spectroscopy of HD${}^{+}$ at the Part-Per-Trillion Level
• Controlling chemical reactions of a single particle
• Proton-electron mass ratio by high-resolution optical spectroscopy of ion ensembles in the resolved-carrier regime
• Opportunities for Fundamental Physics Research with Radioactive Molecules
• Trapping, cooling, and photodissociation analysis of state-selected H$\_2^{+}$ ions produced by (3+1) multiphoton ionization
• Generation of rotational ground state HD${}^{+}$ ions in an ion trap using a resonance-enhanced threshold photoionization process
• Quantum state tracking and control of a single molecular ion in a thermal environment
• Third-harmonic-generation of a diode laser for quantum control of beryllium ions
• Prospect for precision quantum logic spectroscopy of vibrational overtone transitions in molecular oxygen ions

Cited by in corpus (1)

• State-Selective Ionization and Trapping of Single H${}_2^{+}$ Ions with (2+1) Multiphoton Ionization