Rydberg atoms offer a unique way to realize the Kelvin, which will substantially improve the reliability and accuracy of radiometry, thermometry, remote sensing, RF communications, and frequency standards. In particular, Rydberg states are perturbed by thermal or blackbody radiation, and these perturbations can be used to quantify its measure in a direct-to-the-SI way at the 100 ppm level [1]. Unlike standard thermal imagers and pyrometers that are sensitive in the infrared, Rydberg atoms are sensitive in the microwave (20 GHz to 200 GHz, roughly), where the blackbody field is 10,000 times smaller. In this regime, Rydberg atoms could represent a factor of 100 improvement in sensitivity to 300 K blackbody fields, while being primary. Proving the viability of Rydberg atoms to realize the Kelvin in this way requires measuring blackbody-induced transitions through either selective field ionization or fluorescence detection. It also requires developing a multi-level model of these interactions to compare again experiment. This research opportunity is being conducted in collaboration with NIST-Boulder.

[1] E.B. Norrgard, S.P. Eckel, C.L. Holloway, and E.L. Shirley, “Quantum blackbody thermometry” New Journal of Physics 23, 033037 (2021).