High-precision spectroscopy of the HD+ molecule at the 1-p.p.b. level

Abstract

Recently we reported a high precision optical frequency measurement of the (v,L):(0,2)->(8,3) vibrational overtone transition in trapped deuterated molecular hydrogen (HD+) ions at 10 mK temperature. Achieving a resolution of 0.85 parts-per-billion (p.p.b.) we found the experimental value (${\nu }_0=383,407,177.38(41)$ MHz) to be in agreement with the value from molecular theory (${\nu }_{\text{th}}=383,407,177.150(15)$ MHz) within 0.6(1.1) p.p.b. [Biesheuvel et al., Nat. Commun. 7, 10385 (2016)]. This enabled an improved test of molecular theory (including QED), new constraints on the size of possible effects due to 'new physics', and the first determination of the proton-electron mass ratio from a molecule. Here, we provide the details of the experimental procedure, spectral analysis, and the assessment of systematic frequency shifts. Our analysis focuses in particular on deviations of the HD+ velocity distribution from thermal (Gaussian) distributions under the influence of collisions with fast ions produced during (laser-induced) chemical reactions, as such deviations turn out to significantly shift the hyperfine-less vibrational frequency as inferred from the saturated and Doppler-broadened spectrum, which contains partly unresolved hyperfine structure.

arXiv comment22 pages, 20 figures

References in corpus (15)

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• Bounds on fifth forces from precision measurements on molecules
• Addressing and manipulation of individual hyperfine states in cold trapped molecular ions and application to HD^{+} frequency metrology
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• Constraints on extra dimensions from precision molecular spectroscopy
• Theoretical transition frequencies beyond 0.1 ppb accuracy in H${}_2^{+}$, HD${}^{+}$, and antiprotonic helium
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• Hydrogen molecular ions for improved determination of fundamental constants
• The electric quadrupole moment of molecular hydrogen ions and their potential for a molecular ion clock
• Two-photon spectroscopy of trapped HD${}^{+}$ ions in the Lamb-Dicke regime
• Measurement of the Coulomb Logarithm in a Radio-Frequency Paul Trap
• Infrared dynamic polarizability of HD+ rovibrational states
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Cited by in corpus (14)

• Proton-Electron Mass Ratio from Laser Spectroscopy of HD${}^{+}$ at the Part-Per-Trillion Level
• Proton-electron mass ratio by high-resolution optical spectroscopy of ion ensembles in the resolved-carrier regime
• Quantum Forces from Dark Matter and Where to Find Them
• Probing new spin-independent interactions through precision spectroscopy in atoms with few electrons
• Bounding Quantum Dark Forces
• Nonadiabatic rotational states of the hydrogen molecule
• Trapping, cooling, and photodissociation analysis of state-selected H$\_2^{+}$ ions produced by (3+1) multiphoton ionization
• Precision Measurements in Few-Electron Molecules: The Ionization Energy of Metastable ${}^4$He${}_2$ and the First Rotational Interval of ${}^4$He${{}_2}^{+}$
• Mass-selective removal of ions from Paul traps using parametric excitation
• Generation of rotational ground state HD${}^{+}$ ions in an ion trap using a resonance-enhanced threshold photoionization process
• Background-Induced Forces from Dark Relics
• Proton-electron mass ratio from HD${}^{+}$ revisited
• Number-Resolved Detection of Dark Ions in Coulomb Crystals
• Fluorescence calorimetry of an ion crystal