Rydberg Spectroscopy in an Optical Lattice: Blackbody Thermometry for Atomic Clocks

TL;DR

This paper demonstrates that optical Rydberg spectroscopy in an optical lattice can serve as a highly sensitive in situ thermometer for atomic clocks, significantly improving blackbody radiation uncertainty measurements.

Contribution

It introduces a method for in situ blackbody thermometry using Rydberg state spectroscopy with unprecedented sensitivity and accuracy for atomic clock applications.

Findings

Rydberg transitions have 200 times larger frequency sensitivity to blackbody radiation than clock transitions.

Magic wavelength lattices are identified for both Strontium and Ytterbium Rydberg states.

Frequency measurements achieve $10^{-16}$ accuracy, enabling 10 mK temperature resolution.

Abstract

We show that optical spectroscopy of Rydberg states can provide accurate {\em in situ} thermometry at room-temperature. Transitions from a metastable state to Rydberg states with principal quantum numbers of 25 to 30 have 200 times larger fractional frequency sensitivities to blackbody radiation than the Strontium clock transition. We demonstrate that magic wavelength lattices exist for both Strontium and Ytterbium transitions between the metastable and Rydberg states. Frequency measurements of Rydberg transitions with $10^{-16}$ accuracy provide $10 \, \mathrm{mK}$ resolution and yield a blackbody uncertainty for the clock transition of $10^{-18}$.