title: Lattice-induced frequency shifts in Sr optical lattice clocks at the 10(-17) level.
abstract: We present a comprehensive study of the frequency shifts associated with the lattice potential in a Sr lattice clock by comparing two such clocks with a frequency stability reaching 5×10(-17) after a 1 h integration time. We put the first experimental upper bound on the multipolar M1 and E2 interactions, significantly smaller than the recently predicted theoretical upper limit, and give a 30-fold improved upper limit on the effect of hyperpolarizability. Finally, we report on the first observation of the vector and tensor shifts in a Sr lattice clock. Combining these measurements, we show that all known lattice related perturbations will not affect the clock accuracy down to the 10(-17) level, even for lattices as deep as 150 recoil energies.
authors.affiliation: LNE-SYRTE, Observatoire de Paris, CNRS, UPMC, 61 avenue de l'Observatoire, 75014 Paris, France.
authors.forename: P G
authors.initials: PG
authors.lastname: Westergaard
authors.forename: J
authors.initials: J
authors.lastname: Lodewyck
authors.forename: L
authors.initials: L
authors.lastname: Lorini
authors.forename: A
authors.initials: A
authors.lastname: Lecallier
authors.forename: E A
authors.initials: EA
authors.lastname: Burt
authors.forename: M
authors.initials: M
authors.lastname: Zawada
authors.forename: J
authors.initials: J
authors.lastname: Millo
authors.forename: P
authors.initials: P
authors.lastname: Lemonde