title: Atomic clock with 1×10(-18) room-temperature blackbody Stark uncertainty.
abstract: The Stark shift due to blackbody radiation (BBR) is the key factor limiting the performance of many atomic frequency standards, with the BBR environment inside the clock apparatus being difficult to characterize at a high level of precision. Here we demonstrate an in-vacuum radiation shield that furnishes a uniform, well-characterized BBR environment for the atoms in an ytterbium optical lattice clock. Operated at room temperature, this shield enables specification of the BBR environment to a corresponding fractional clock uncertainty contribution of 5.5×10(-19). Combined with uncertainty in the atomic response, the total uncertainty of the BBR Stark shift is now 1×10(-18). Further operation of the shield at elevated temperatures enables a direct measure of the BBR shift temperature dependence and demonstrates consistency between our evaluated BBR environment and the expected atomic response.
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: K
authors.initials: K
authors.lastname: Beloy
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA and University of Colorado, Department of Physics, Boulder, Colorado 80309, USA.
authors.forename: N
authors.initials: N
authors.lastname: Hinkley
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: N B
authors.initials: NB
authors.lastname: Phillips
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Sherman
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: M
authors.initials: M
authors.lastname: Schioppo
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: J
authors.initials: J
authors.lastname: Lehman
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: A
authors.initials: A
authors.lastname: Feldman
authors.affiliation: National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA.
authors.forename: L M
authors.initials: LM
authors.lastname: Hanssen
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: C W
authors.initials: CW
authors.lastname: Oates
authors.affiliation: National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: A D
authors.initials: AD
authors.lastname: Ludlow