Bulletin of the American Physical Society
50th Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics APS Meeting
Volume 64, Number 4
Monday–Friday, May 27–31, 2019; Milwaukee, Wisconsin
Session D04: Precision Measurements with Molecules |
Hide Abstracts |
Chair: May Kim, NIST Room: Wisconsin Center 102AB |
Tuesday, May 28, 2019 2:00PM - 2:12PM |
D04.00001: Precision proton-deuteron mass ratio from cyclotron frequency measurements of H$_{2}^{+}$ and D$^{+}$ with H$_{2}^{+}$ in the vibrational ground-state David J Fink, Edmund G Myers Precision measurements of the CFR (cyclotron frequency ratio) of H$_{2}^{+}$ to D$^{+}$ provide an effective means to determine the mass ratio of the proton and deuteron $m_{p}/m_{d}$. Comparison of ions of nearly equal mass results in a large reduction in systematic errors. When the H$_{2}^{+}$ is produced by electron-impact ionization of H$_{2}$ this process is made more complicated because the H$_{2}^{+}$ can be formed in one of 20 vibrational levels, which significantly affects its mass. For instance, the energy difference between $v=1$ and $v=0$ ($J= 0$) corresponds to a fractional change in mass of 1.45 x 10$^{-10}$. However, since our CFR resolution is sufficient to resolve this difference, we can identify the ground vibrational level. In addition, we can accelerate the decay from excited vibrational levels to the ground level by means of Stark-quenching, by placing the H$_{2}^{+}$ in a large cyclotron orbit. The status of our measurements and study of systematics will be presented. [Preview Abstract] |
Tuesday, May 28, 2019 2:12PM - 2:24PM |
D04.00002: Blackbody thermometry with quantum state control of trapped SiO$^{\mathrm{+}}$ Sruthi Venkataramanababu, Patrick Stollenwerk, Ivan Antonov, Brian Odom Despite the complex internal structure of molecules, we have demonstrated a technique based on spectral pulse-shaping with a broadband laser to arbitrarily populate a narrow distribution of rotational states (upto N 65) in the ground electronic state of SiO$^{\mathrm{+}}$. We use a 1-photon resonance enhanced dissociation via a $\prod $ state that is sufficiently long-lived to resolve rotational transitions in SiO$^{\mathrm{+}}$. For precision measurements of frequency using ion traps, measuring the blackbody radiation (BBR) is critical and in-situ trapped ion BBR thermometer is a promising solution.~The combined ability to cool and carry out state readout opens the possibility of using rotational transitions in trapped molecular ions for BBR thermometry. In the first use of trapped molecules as a BBR thermometer [1], the molecular ions were allowed to equilibrate with the black body field. However, with our ability to prepare the sample in rotational states of our choice, we can probe the different spectral components of the blackbody field and thus create a spectral map for the BBR field. As a first step towards this goal, we are in the process of studying population dynamics and time scales for population distribution using single photon dissociation. I will discuss results from this work and possible techniques for black-body thermometry with our system. 1. Koelemeij, J.C.J., et.al. Phys. Rev. A 76, 23413. doi:10.1103/PhysRevA.76.023413 [Preview Abstract] |
Tuesday, May 28, 2019 2:24PM - 2:36PM |
D04.00003: Fine and hyperfine structure of $^{\mathrm{173}}$YbF Richard Mawhorter, EliseAnne Koskelo, Graceson Aufderheide, Jens-Uwe Grabow, Timothy Steimle, Hailing Wang $^{\mathrm{174}}$YbF has been used for some time in attempts to determine the electrostatic T,P violating electron electric dipole moment (eEDM). It was recently pointed out [1] that $^{\mathrm{173}}$YbF may be an avenue for determining an EDM induced by the magnetic quadrupole moment (MQM). As in the eEDM case, here the molecular properties of $^{\mathrm{173}}$YbF are experimentally advantageous. We report a detailed analysis of the fine and hyperfine structure in the $X^{\mathrm{2}}\Sigma^{\mathrm{+}}$ state from a combined analysis of rotational and optical transitions. Numerous hyperfine components in the $N=$4-5 and $N=$3-4 rotational transitions were recorded using a separated field pump/probe microwave optical double residence technique. Fourier transform microwave spectroscopy was used to record five features of the $N=$0-1 rotational transition. This rotational data was combined with precisely measured (0,0) A$^{\mathrm{2}}\Pi _{\mathrm{1/2}}-X^{\mathrm{2}}\Sigma^{\mathrm{+}}$ optical transitions of a cold molecular beam sample. Resulting fine and hyperfine parameters will be discussed and compared with recent theory [2]. 1. V.V. Flambaum, et al., arXiv:1810.02477v2 [hep-ph] (10 Dec 2018) 2. P. Schwerdtfeger, et al., Mol. Phys. \textbf{114}, 1110 (2016) [Preview Abstract] |
Tuesday, May 28, 2019 2:36PM - 2:48PM |
D04.00004: Two-Photon Vibrational Transitions in O$_2^+$ as Probes of Variation of the Proton-to-Electron Mass Ratio David Hanneke, Ryan Carollo, Alexander Frenett Molecular vibrations provide sensitive probes for variation of the proton-to-electron mass ratio $\mu$. The O$_2^+$ molecule has many vibrational overtone transitions that appear capable of detecting change at the $10^{-18}$ level or better [1]. Here we report calculations of two-photon transition rates, systematic effects, and achievable statistical precision for measurements using these overtones. We present results of state preparation via photoionization and progress towards driving the transitions and detection via photodissociation. [1] R. Carollo, A. Frenett, D. Hanneke, Atoms v.7, 1 (2019) [Preview Abstract] |
Tuesday, May 28, 2019 2:48PM - 3:00PM |
D04.00005: Photon Recoil Readout in a Two-Ion Crystal of Ba$^+$ and AlH$^+$ James Dragan, Qiming Wu, Greg Rabelo, Brian Odom By entangling the internal quantum state of a target ion to the motional state of another logic ion, the Quantum Logic Spectroscopy (QLS) scheme has been used to make precision measurements of narrow atomic transitions, most notably in the NIST Al$^+$ clock. As a first step towards implementation of molecular QLS, we present our progress towards Photon Recoil Readout (PRR). Using PRR we excite motion in a two-ion crystal, AlH$^+$ (m = 28 amu) and Ba$^+$ (m = 138 amu), by driving repeated molecular photon recoil events at a rate equal to the axial out-of-phase mode. Scattering at this resonant frequency, we expect that only 10 recoil events are sufficient to excite the ion pair to n = 1 stretch mode. Although specific to the choice of molecular ion, PRR is easier than QLS to implement experimentally since it relaxes the constraints of the required light-matter coherence times and narrow laser linewidth. [Preview Abstract] |
Tuesday, May 28, 2019 3:00PM - 3:12PM |
D04.00006: Vibrational molecular lattice clock for fundamental physics Kon Leung, Chih-Hsi Lee, Stanimir Kondov, Tanya Zelevinsky A molecular clock operating on rovibrational transitions is a promising instrument in the search for variations of the electron-to-proton mass ratio, presence of gravity-like forces at the nanometer-scale, and QED corrections to long-range interatomic interactions. I report the realization of a lattice clock with ultracold diatomic strontium, enabled by state-insensitive trapping of electronic ground-state molecules in an optical lattice tuned close to a narrow vibronic resonance belonging to the potential correlating to the atomic spin-forbidden intercombination line. At this magic wavelength, we observe more than a thousand-fold improvement in light-molecule coherence, achieving a $Q$ factor of almost $10^{12}$. I also discuss the ongoing systematic evaluation and conclude with an outlook for high-precision measurements with the molecular clock. [Preview Abstract] |
Tuesday, May 28, 2019 3:12PM - 3:24PM |
D04.00007: Projection noise limited precision measurement in polar molecules with photofragment imaging William B. Cairncross, Kia Boon Ng, Tanya S. Roussy, Yan Zhou, Yuval Shagam, Tanner Grogan, Madeline Pettine, Antonio Vigil, Kevin Boyce, Tanya Zelevinsky, Jun Ye, Eric A. Cornell Molecules are increasingly used for precision measurements due to their high sensitivity to new physics, including permanent electric dipole moments and dark matter. However, molecules with high sensitivity often do not have optical cycling transitions for efficient fluorescence detection, limiting measurement precision. Photoionization and dissociation are versatile tools with high quantum efficiency, but often suffer from technical noise common to pulsed UV lasers. We demonstrate a new method for differential quantum phase measurement in polar molecules that overcomes this limitation by imaging the products of a molecular orientation-preserving photodissociation. We apply this method in HfF$^{\mathrm{+}}$, along with efficient state preparation via optical pumping, to attain a projected statistical sensitivity to the electron's electric dipole moment of 2 x 10$^{\mathrm{-29}} \quad e$ cm in one hour of integration time. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700