Seminarium Optyczne

The energetic structure of atoms and molecules is determined by the interaction between their components and the surrounding space. Therefore atoms can be used to look for perturbation by dark matter fields. On the other hand, molecules are especially attractive to test quantum electrodynamics (QED) in systems more complex than a single atom and look for more exotic interactions like hadron-hadron fifth forces or short range non-Newtonian gravitation. It was demonstrated that even a single optical atomic clock can be sensitive to coupling with a possible dark matter field and the global network of such sensors was arranged. Doppler limited cavity-ring down spectra of D2 analysed with ab initio line shape profiles provided an accurate experimental test of QED calculations for this system. A proof-of-principle demonstration of use of photoassociation spectroscopy of weakly bound molecules was carried with ultracold Yb2 for determination of constraints on fifth forces or non-Newtonian interactions between atoms. Prospects for farther improvement of discussed techniques can be seen in a pure frequency dispersion spectroscopy, development of optical molecular clocks and use of ultracold systems involving Hg atoms. Moreover, new areas of investigations are opened by laser cooling of positronium.