Sebastien Bize

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The frequencies of a cryogenic sapphire oscillator and a hydrogen maser are compared to set new constraints on a possible violation of Lorentz invariance. We give a detailed description of microwave resonators operating in Whispering Gallery modes and then apply it to derive explicit models for Lorentz violating effects in our experiment. Models are(More)
We present a new evaluation of an 87 Sr optical lattice clock using spin polarized atoms. The frequency of the 1 S0 → 3 P0 clock transition is found to be 429 228 004 229 873.6 Hz with a fractional accuracy of 2.6 × 10 −15 , a value that is comparable to the frequency difference between the various primary standards throughout the world. This measurement is(More)
Optical and radio frequency standards located in JILA and National Institute of Standards and Technology (NIST) laboratories have been connected through a 3.45-km optical fiber link. An optical frequency standard based on an iodine-stabilized Nd:YAG laser at 1064 nm (with an instability of ϳ4 ϫ 10 Ϫ14 at 1 s) has been transferred from JILA to NIST and(More)
The frequencies of a cryogenic sapphire oscillator and a hydrogen maser are compared to set new constraints on a possible violation of Lorentz invariance. We determine the variation of the oscillator frequency as a function of its orientation (Michelson-Morley test) and of its velocity (Kennedy-Thorndike test) with respect to a preferred frame candidate. We(More)
Testing the stability of fundamental constants with the 199 Hg + single-ion optical clock Over a two-year duration, we have compared the frequency of the 199 Hg + 5d 10 6s 2 S 1/2 (F = 0) ←→ 5d 9 6s 2 2 D 5/2 (F = 2) electric-quadrupole transition at 282 nm with the frequency of the ground-state hyperfine splitting in neutral 133 Cs. These measurements show(More)
— We propose a novel experiment based on atoms trapped close to a macroscopic surface, to study the interactions between the atoms and the surface at very small separations (0.6 to 10 µm). In this range the dominant potential is the QED interaction (Casimir-Polder and Van der Waals) between the surface and the atom. Additionally, several theoretical models(More)
We review our recent Michelson-Morley (MM) and Kennedy-Thorndike (KT) experiment, which tests Lorentz invariance in the photon sector, and report first results of our ongoing atomic clock test of Lorentz invariance in the matter sector. The MM-KT experiment compares a cryogenic microwave resonator to a hydrogen maser, and has set the most stringent limit on(More)