Cryogenic Optical Lattice Clock with 1.7×10^{-20} Blackbody Radiation Stark Uncertainty

Area of Science:

• Atomic, Molecular, and Optical Physics
• Metrology and Measurement Science
• Quantum Information Science

Background:

• Controlling Stark perturbation from ambient thermal radiation is crucial for advancing atomic frequency standards, particularly optical lattice clocks (OLCs).
• Previous cryogenic blackbody radiation (BBR) control solutions in OLCs faced limitations in shielding effectiveness.

Purpose of the Study:

• To demonstrate a cryogenic OLC with a dynamically actuated radiation shield for superior Stark perturbation control.
• To independently measure and verify the BBR Stark dynamic correction coefficient for ytterbium (Yb).

Main Methods:

• Development and implementation of a cryogenic OLC featuring a dynamically actuated radiation shield.
• Utilizing the shield to create a near-ideal cryogenic BBR environment, rejecting external thermal radiation at the part-per-million level during spectroscopy.
• Exploiting the shield's radiation control over a wide temperature range for coefficient measurement.

Main Results:

• Achieved a Stark perturbation control at 1.7×10⁻²⁰ fractional frequency, approximately 40 times better than previous state-of-the-art OLCs.
• Reduced the uncertainty of the leading BBR Stark dynamic correction coefficient for Yb by 30%.
• Verified the static BBR coefficient for Yb at the 10⁻¹⁸ level.

Conclusions:

• The demonstrated cryogenic OLC with a dynamic radiation shield significantly advances BBR control for atomic frequency standards.
• The independent measurement of the Yb BBR Stark dynamic correction coefficient benefits current and future Yb OLCs, including those operated at room temperature.