Gianmaria Milani

TL;DR: Local optical clock measurements that surpass the current ability to account for the gravitational distortion of space-time across the surface of Earth are demonstrated and improved techniques allow the measurement of a frequency difference with an uncertainty of the order of 10–19 between two independent optical lattice clocks, suggesting that they may be able to improve state-of-the-art geodetic techniques.

TL;DR: In this paper, a zero-dead-time optical clock based on interleaved interrogation of two cold-atom ensembles has been proposed to overcome the Dick effect, which results in an aliasing of frequency noise from the laser interrogating the atomic transition.

TL;DR: In this paper, two independent ytterbium optical lattice clocks were used to demonstrate unprecedented levels in three fundamental benchmarks of clock performance: systematic uncertainty of $1.4, measurement instability of $3.2, and reproducibility characterised by ten blinded frequency comparisons, yielding a frequency difference of $[-7 \pm (5)stat} \pm(8)_{sys}] \times 10^{-19}

TL;DR: An "operational" magic wavelength is identified where frequency shifts are insensitive to changes in trap depth, and measurements and scaling analysis constitute an essential systematic characterization for clock operation at the 10-18 level and beyond.

TL;DR: The absolute frequency measurement of the unperturbed transition at 578 nm in 171Yb realized in an optical lattice frequency standard relative to a cryogenic caesium fountain was reported in this article.