Zak Burkley (ETH Zurich)

 Exciting Exotic Atoms: Precision Spectroscopy of Muonium at PSI 

 Recent and ongoing developments of low energy muon beamlines, paired with the development of efficient muon-muonium converters and laser advancements, is heralding a new era of precision Muonium spectroscopy. In this talk I will give an overview of the current status and future prospects of two new experiments currently underway at the LEM beamline at PSI and ETH, Mu-LaMB and Mu-MASS, which aim to improve the precision of both the Muonium Lamb shift and 1S-2S transition by several orders of magnitude, respectively. I will highlight our recent developments critical for such improvements, i.e., efficient production, tagging and detection of metastable Muonium in vacuum, and a robust, high power 244 nm laser system that will enable CW, doppler-free two-photon excitation of the Muonium 1S-2S transition.

Alejandra Collopy (NIST)

 Expanding the molecular ion control toolbox with quantum logic

Quantum logic enables state preparation, readout and spectroscopy of otherwise difficult-to-study ions. Using the coupled harmonic motion shared between co-trapped ions, information can be transferred from the "spectroscopy" ion to the easily manipulated "logic" ion. With this technique we perform high-resolution terahertz-scale rotational spectroscopy of a single CaH+ molecular ion in pure states by leveraging a Ca+ ion as our logic ion. Entangled states between a CaH+ and a Ca+ have also been demonstrated, making molecular ions possible components of hybrid systems for quantum information processing. Because all our laser operations on the molecule are driving stimulated Raman transitions with high detuning, the technique promises to be generalizable to a wide variety of molecular ion species. Additionally, we study the systematic effects of the trap RF electric field on molecular levels and use it to obtain a measurement of the dipole moment of the charged molecule.

C.-W. Chou, A. L. Collopy, C. Kurz, Y. Lin, M. E. Harding, P. N. Plessow, T. Fortier, S. Diddams, D. Leibfried, D. R. Leibrandt, Science 367,6485 (2020)

Y. Lin D. R. Leibrandt, D. Leibfried, C.-W. Chou, Nature 581, 273-277 (2020)