Francis M. Pipkin Award: State-of-the-Art Optical Clocks and the Search for New Physics

Atomic clocks based on electronic transitions in the optical domain are now capable of measuring time

at eighteen digits of precision. At this level, it becomes challenging to form large-scale timing networks

on Earth, due to present-day limits in accounting for gravitational effects on time. Nevertheless, when

measurements between either similar or diverse species of optical atomic clocks can be made at the

highest levels, they offer a sensitive probe for testing the fundamental laws of nature or searching for

physics beyond the Standard Model. I highlight this by exploring recent measurements and

developments with the ytterbium optical lattice clock at NIST. Cutting-edge measurements between

ytterbium and strontium optical lattice clocks and the Al + quantum logic clock enable a search for

ultralight scalar dark matter, while a global observatory of optical clocks probes topological dark matter.

I discuss the growing push to take these ultra-precise devices outside the laboratory, for tests of general

relativity and mapping the earth’s geopotential beyond the current state-of-the-art. Finally, I describe

how new techniques and enhanced strategies for quantum control in optical lattice clocks are paving the

way towards measurement beyond the 10 -19 level, to realize a new reach in fundamental physics tests.