@article{f51813e51291470291f6ba3936eaf4a1,
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 = "AMER PHYSICAL SOC",
number = "3",
}