Optical lattice clocks for fundamental physics and application

Atomic clocks are the pillars of the global timescale (UTC). Accurate timing and synchronization are essential ingredients in various technologies such as electronic communications and navigation. Optical atomic clocks use optical frequencies or lasers to generate a stable frequency, and this finer resolution leads to about 100 times better precision and accuracy than the current primary standard based on the microwave transition of cesium. Optical clocks now reach fractional frequency uncertainties below 10⁻¹⁸, pressing toward a redefinition of the second. With such precision, optical clocks can be used in new areas of application, such as relativistic height sensing and tests of fundamental physics.

Optical lattice clocks are one of the most successful architectures that harness laser cooling and trapping technologies for probing many ultracold atoms simultaneously. As we zoom in to narrower frequency ranges, we encounter challenges that test our fundamental understanding of atom-light and atom-atom interactions, demanding cutting-edge laser stabilization and quantum state control.

In this talk, we introduce optical lattice clock experiments at JILA and discuss the physics we can learn from them, including quantum many-body dynamics and quantum optical aspects. With an improved uncertainty budget, we compare our clock against two state-of-the-art optical clocks at NIST. We also present recent efforts toward generating an all-optical precision timing signal and discuss the associated benefits and challenges.