Physics Department Colloquium
An amazing level of quantum control is routinely reached in modern experiments with atoms, but similar control over molecules has been an elusive goal. We recently proposed a method based on quantum logic spectroscopy  to address this problem for a wide class of molecular ions . We have now realized the basic elements of this proposal. In our demonstration, we trap a calcium ion together with a calcium hydride ion (CaH+) that is a convenient stand-in for more general molecular ions.
Neutrino oscillations provide the first hints at physics beyond the standard model of particle physics. Current and future neutrino experiments aim to further refine our understanding of neutrino mixing and reveal the remaining unknowns in the process. Precision measurements in long-baseline accelerator experiments could help answer profound questions about the origin and evolution of our universe, including the assymetry of matter over antimatter.
Laser cooled trapped ions offer unprecedented control over both internal and external degrees of freedom at the single-particle level. They are considered among the foremost candidates for realizing quantum simulation and computation platforms that can outperform classical computers at specific tasks. In this talk I will show how linear arrays of trapped 171Yb+ ions can be used as a versatile platform for studying quantum dynamics of strongly correlated many-body quantum systems.
Measurements of the fine-structure constant alpha require methods from several subfields and are thus powerful tests of the consistency of theory and experiment in physics. Using the recoil frequency of cesium-133 atoms in a matter-wave interferometer, we recorded the most accurate measurement of the fine-structure constant to date: alpha = 1/137.035999046(27) at 2.0 x 10^-10 accuracy.