Optical clocks based on highly charged ions for improved frequency standards and tests of fundamental physics

Optical clocks based on highly charged ions (HCIs) offer a number of promising avenues for the study of physics beyond the standard model. Among these are searches for time variation of the fine structure constant, (̇α/α), and tests of quantum electrodynamics (QED). Due to level crossings occurring in high charge states, narrow linewidth, optically accessible transitions with a high sensitivity to ̇α/α are predicted in both Nd¹⁰⁺ and Pr¹⁰⁺. We present the status of an ongoing experimental program to perform high-precision, quantum-enabled laser spectroscopy of transitions in these ions. We plan to first create HCIs in a compact electron beam ion trap (EBIT) and then transfer them to a radiofrequency (rf) Paul trap where quantum-logic spectroscopy (QLS) will be performed. In addition, we present an update on the development of a Ba⁴⁺ quantum-logic clock as an improved optical frequency standard and an optical fiber link between CSU and the NIST-WWV clock ensemble located in Fort Collins, CO.