@article{10dbdc128119477e840938be2866a838,
title = "Optical atomic clock comparison through turbulent air",
abstract = "We use frequency-comb-based optical two-way time-frequency transfer (O-TWTFT) to measure the optical frequency ratio of state-of-the-art ytterbium and strontium optical atomic clocks separated by a 1.5-km open-air link. Our free-space measurement is compared to a simultaneous measurement acquired via a noise-cancelled fiber link. Despite nonstationary, ps-level time-of-flight variations in the free-space link, ratio measurements obtained from the two links, averaged over 30.5 hours across six days, agree to 6×10-19, showing that O-TWTFT can support free-space atomic clock comparisons below the 10-18 level.",
author = "Bodine, \{Martha I.\} and Desch{\^e}nes, \{Jean Daniel\} and Khader, \{Isaac H.\} and Swann, \{William C.\} and Holly Leopardi and Kyle Beloy and Tobias Bothwell and Brewer, \{Samuel M.\} and Bromley, \{Sarah L.\} and Chen, \{Jwo Sy\} and Diddams, \{Scott A.\} and Fasano, \{Robert J.\} and Fortier, \{Tara M.\} and Hassan, \{Youssef S.\} and Hume, \{David B.\} and Dhruv Kedar and Kennedy, \{Colin J.\} and Amanda Koepke and Leibrandt, \{David R.\} and Ludlow, \{Andrew D.\} and Mcgrew, \{William F.\} and Milner, \{William R.\} and Daniele Nicolodi and Eric Oelker and Parker, \{Thomas E.\} and Robinson, \{John M.\} and Stefania Romish and Sch{\"a}ffer, \{Stefan A.\} and Sherman, \{Jeffrey A.\} and Lindsay Sonderhouse and Jian Yao and Jun Ye and Xiaogang Zhang and Newbury, \{Nathan R.\} and Sinclair, \{Laura C.\}",
note = "Publisher Copyright: {\textcopyright} 2020 authors. Published by the American Physical Society.",
year = "2020",
month = sep,
doi = "10.1103/PhysRevResearch.2.033395",
language = "English",
volume = "2",
journal = "Physical Review Research",
issn = "2643-1564",
publisher = "American Physical Society",
number = "3",
}