T. Nicholson, Systematic evaluation of an atomic clock at 2 ?? 10???18 total uncertainty, Nature Communications, vol.331, p.6896, 2015.
DOI : 10.1126/science.1196442

J. Lodewyck, Optical to microwave clock frequency ratios with a nearly continuous strontium optical lattice clock Metrologia, p.1123, 2016.
DOI : 10.1088/0026-1394/53/4/1123
URL : http://arxiv.org/abs/1605.03878

C. Lisdat, 2016 A clock network for geodesy and fundamental science Nat, Commun, vol.7, p.12443
DOI : 10.1038/ncomms12443
URL : http://doi.org/10.1038/ncomms12443

M. Schioppo, Ultrastable optical clock with two cold-atom ensembles Nat. Photon, p.48, 2017.
DOI : 10.1038/nphoton.2016.231
URL : http://arxiv.org/abs/1607.06867

S. Häfner, S. Falke, C. Grebing, S. Vogt, T. Legero et al., fractional laser frequency instability with a long room-temperature cavity Opt, Lett, vol.40, pp.2112-2117

T. Kessler, C. Hagemann, C. Grebing, T. Legero, U. Sterr et al., A sub-40-mHz-linewidth laser based on a silicon single-crystal optical cavity, Nature Photonics, vol.2, issue.10, pp.687-92, 2012.
DOI : 10.1364/JOSAB.2.001527

Q. Chen, A. Troshyn, I. Ernsting, S. Kayser, S. Vasilyev et al., Crystal at Cryogenic Temperature, Physical Review Letters, vol.107, issue.22, p.223202, 2011.
DOI : 10.1038/nphoton.2011.215

D. Meiser, J. Ye, D. R. Carlson, and M. Holland, Prospects for a Millihertz-Linewidth Laser, Physical Review Letters, vol.17, issue.16, p.163601, 2009.
DOI : 10.1143/JPSJ.17.1100

J. Lodewyck, P. G. Westergaard, and P. Lemonde, Nondestructive measurement of the transition probability in a Sr optical lattice clock, Physical Review A, vol.48, issue.6, p.61401, 2009.
DOI : 10.1103/PhysRevLett.100.103601

R. Kohlhaas, A. Bertoldi, E. Cantin, and A. Aspect, Landragin A and Bouyer P 2015 Phase locking a clock oscillator to a coherent atomic ensemble Phys. Rev, p.21011

O. Hosten, N. J. Engelsen, R. Krishnakumar, and M. A. Kasevich, Measurement noise 100 times lower than the quantum-projection limit using entangled atoms, Nature, vol.111, issue.7587, p.505, 2016.
DOI : 10.1103/PhysRevLett.111.090801

M. H. Schleier-smith, I. Leroux, and V. Vuleti?, Squeezing the collective spin of a dilute atomic ensemble by cavity feedback, Physical Review A, vol.81, issue.2, p.21804, 2010.
DOI : 10.1126/science.1148259

K. C. Cox, G. P. Greve, B. Wu, and J. Thompson, Spatially homogeneous entanglement for matter-wave interferometry created with time-averaged measurements, Physical Review A, vol.94, issue.6, p.61601, 2016.
DOI : 10.1103/PhysRevLett.99.093902
URL : http://arxiv.org/abs/1608.06234

D. Oblak, P. G. Petrov, C. Alzar, W. Tittel, A. K. Vershovski et al., Quantum-noise-limited interferometric measurement of atomic noise: Towards spin squeezing on the Cs clock transition, Physical Review A, vol.42, issue.4, p.43807, 2005.
DOI : 10.1103/PhysRevA.71.033803

R. Inoue, Unconditional Quantum-Noise Suppression via Measurement-Based Quantum Feedback, Physical Review Letters, vol.110, issue.16, p.163602, 2013.
DOI : 10.1038/nphys1821
URL : http://arxiv.org/abs/1301.1016

I. D. Leroux, M. Schleier-smith, and V. Vuleti?, Orientation-Dependent Entanglement Lifetime in a Squeezed Atomic Clock, Physical Review Letters, vol.103, issue.25, p.250801, 2010.
DOI : 10.1103/PhysRevA.79.061401
URL : http://arxiv.org/pdf/1004.1725

A. Kuzmich, N. P. Bigelow, and L. Mandel, Atomic quantum non-demolition measurements and squeezing Europhys, Lett, vol.42, p.481, 1998.
DOI : 10.1209/epl/i1998-00277-9

D. J. Wineland, J. J. Bollinger, W. M. Itano, and D. J. Heinzen, Squeezed atomic states and projection noise in spectroscopy, Physical Review A, vol.65, issue.1, pp.67-88, 1994.
DOI : 10.1103/PhysRevLett.65.2347

E. Polzik and J. Ye, Entanglement and spin squeezing in a network of distant optical lattice clocks, Physical Review A, vol.93, issue.2, p.21404, 2016.
DOI : 10.1038/nphys3366

P. J. Windpassinger, D. Oblak, P. G. Petrov, M. Kubasik, M. Saffman et al., Nondestructive Probing of Rabi Oscillations on the Cesium Clock Transition near the Standard Quantum Limit, Nondestructive probing of rabi oscillations on the cesium clock transition near the standard quantum limit, p.103601, 2008.
DOI : 10.1209/epl/i1998-00277-9

S. Bernon, T. Vanderbruggen, R. Kohlhaas, A. Bertoldi, A. Landragin et al., Heterodyne non-demolition measurements on cold atomic samples: towards the preparation of non-classical states for atom interferometry, New Journal of Physics, vol.13, issue.6, p.65021, 2011.
DOI : 10.1088/1367-2630/13/6/065021
URL : https://hal.archives-ouvertes.fr/hal-00574298

M. Kohnen, P. G. Petrov, R. A. Nyman, and E. Hinds, Minimally destructive detection of magnetically trapped atoms using frequency-synthesized light, New Journal of Physics, vol.13, issue.8, p.85006, 2011.
DOI : 10.1088/1367-2630/13/8/085006
URL : http://doi.org/10.1088/1367-2630/13/8/085006

J. Béguin, E. M. Bookjans, S. L. Christensen, H. L. Sørensen, J. H. Müller et al., Generation and Detection of a Sub-Poissonian Atom Number Distribution in a One-Dimensional Optical Lattice, Physical Review Letters, vol.113, issue.26, p.263603, 2014.
DOI : 10.1364/OL.37.001949

M. H. Schleier-smith, I. Leroux, and V. Vuleti?, States of an Ensemble of Two-Level Atoms with Reduced Quantum Uncertainty, Physical Review Letters, vol.104, issue.7, p.73604, 2010.
DOI : 10.1103/PhysRevLett.104.073602

H. Zhang, R. Mcconnell, S. ?uk, Q. Lin, M. H. Schleier-smith et al., Collective State Measurement of Mesoscopic Ensembles with Single-Atom Resolution, Physical Review Letters, vol.109, issue.13, p.133603, 2012.
DOI : 10.1103/PhysRevLett.107.143005

J. Ye, L. Ma, and J. Hall, Ultrasensitive detections in atomic and molecular physics: demonstration in molecular overtone spectroscopy, Journal of the Optical Society of America B, vol.15, issue.1, pp.6-15, 1998.
DOI : 10.1364/JOSAB.15.000006
URL : http://authors.library.caltech.edu/5475/1/YEJjosab98.pdf

J. Lee, G. Vrijsen, I. Teper, O. Hosten, and M. A. Kasevich, Many-atom cavity QED system with homogeneous atom-cavity coupling Opt, Lett, vol.39, pp.4005-4013, 2014.
DOI : 10.1364/ol.39.004005
URL : http://arxiv.org/pdf/1311.1805