Physics in Dual-Species Ion Chains

Systems of trapped atomic and molecular ions can be exquisitely controlled in the laboratory, making them well-suited for use both as the `engine' for emulating quantum phenomena and also as a powerful resource for fundamental physics.  Our laboratory is working towards experiments on both of these fronts.  In the first, we are constructing a two-ion thermal rectifier using Ca⁺ and Sr⁺, our first foray into trapped-ion phononics wherein we seek to demonstrate control over the flow of heat in ways analogous to existing technological control over electrical currents (electronics) and light (photonics).  EIT cooling simulates a thermal reservoir attached to each ion, while sideband thermometry probes heat flow within the chain.  For the second, we will discuss plans for a series of precision isotope shift measurements in the CaH⁺ ion, implementing projective state preparation and quantum logic spectroscopy to probe Raman transitions driven with an optical frequency comb.  When combined with theory, such measurements can explore corrections to the point-nucleus approximation typically used in calculating molecular rotational constants, offering a window into the nuclear mass distribution and exploring fundamental questions of how nucleons are distributed within the calcium nucleus.