Atomic diffraction through a nano grating
Gabriel Dutier, Nathalie Fabre, Francisco Perales, Martial Ducloy, Hanane Bricha Tazi (PhD), Franck Correia (PhD)
Former members: Jacques Baudon, Thierry Taillandier-Loize, Mehdi Hamamda, Jules Grucker
Atomic diffraction through a nanogratings with supersonic beams started with their fabrication in 2000. Such experiments allowed probing Casimir Polder potential between fast atoms and nanograting bars. We propose a unique experimental set up  in order to redo this experiments but at lower velocities between 10 and 150 m/s with metastable argon. The atomic wave packet phase is proportional to the time duration of the atom surface interaction, which becomes dominant on the grating geometrical diffraction and lead to a very high potential sensitivity.
These experiments lead to a much better quality of the theoretical model, which is not better than 5 to 10 % actually . The atomic beam coherence allows observing the two slits diffraction regards to the envelope, which is only governed by Casimir Polder interaction. We are currently working to make such a nanograting at the University Paris 13 clean room facility. Several sizes could be provided in order to build the scale law of the potential (non retarded to retarded regime). Using the 36Ar isotope would constraint the hypothetical deviation to a non Newtonian gravitational potential at very short distances with comparison to 40Ar spectra.
Diffraction picture of metastable argon through a nanograting of 50 nm at 20 m/s. Abscissa axis is in mm on a time-position detector. Diffraction pics come from two slits diffraction and the envelopp is gouverned by Casimir-Polder interaction.
 Taillandier Loize T., Aljunid S.A., Correia F., Fabre N., Perales F., Tualle J.-M., Baudon J., Ducloy M., Dutier G.,
A simple velocity-tunable pulsed atomic source of slow metastable argon,
Journal of Physics D: Applied Physics, 49, 13, 135503, (2016).
 Hamamda M., Boustimi M., Bocvarsky V., Taillandier Loize T., Dutier G., Perales F., Baudon J., Ducloy M.,
Atom-surface interaction at the nanometre scale: van der Waals-Zeeman transitions in a magnetic field,
Europhysics Letters, 98, 23001, (2012).