Tests of Fundamental Physics, Atom Interferometry and Metrology

Atom Interferometry and Metrology

The cryogenic resonator, the atomic fountain clocks and the optical clocks available at SYRTE are used in order to realize tests of fundamental physics: variation of fundamental constants, Lorentz invariance, interactions at short distances, etc. Theoretical frameworks beyond the standard model are studied and employed for the modeling of the experiments and the data analysis. Fundamental perturbing effects like the recoil of the atom in atomic frequency measurements and the use of gravity in optical lattice clocks are modeled.

The theory of atom interferometry in a gravitational field is developed and applied to the conception of new space-time sensors using coherent matter waves (produced for example by Bose-Einstein condensates) for terrestrial and space applications: clocks, gyro/accelerometers, gravitational wave detectors, atomic cavities. The calculation of relativistic phase shifts for particles with spin and research on atom-wave propagation and amplification are pursued. A new 5D atom optics using proper time quantization is elaborated. Theoretical investigations related to possible changes of the SI unit system are carried out in depth.

Left: Measurements of atomic frequencies as a function of diurnal spin orientation, searching for a putative violation of Lorentz invariance [Phys. Rev. Lett. 96, 060801, 2006].
Right: Atom trajectories for a multiple-wave Ramsey-Bordé interferometer levitating in the Earth gravity field.

Contact