[1] Leibniz Univ Hannover, Inst Theoret Phys, Appelstr 2, D-30167 Hannover, Germany
[2] Leibniz Univ Hannover, Inst Quantenopt, Welfengarten 1, D-30167 Hannover, Germany
[3] Leibniz Univ Hannover, Deutsch Zentrum Luft & Raumfahrt eV DLR, DLR SI, Inst Satellitengeodasie & Inertialsensor, Callinstr 36, D-30167 Hannover, Germany
[4] CNR, INO, QSTAR, Largo Enrico Fermi 2, I-50125 Florence, Italy
[5] Sorbonne Univ, Coll France, Univ PSL, Lab Kastler Brossel,ENS,CNRS, 24 Rue Lhomond, F-75005 Paris, France