Influence of conformational molecular dynamics on matter wave interferometry

We investigate the influence of thermally activated internal mol. dynamics on the phase shifts of matter waves inside a mol. interferometer. While de Broglie physics generally describes only the center-of-mass motion of a quantum object, our expt. demonstrates that the translational quantum phase is sensitive to dynamic conformational state changes inside the diffracted mols. The structural flexibility of tailor-made org. particles is sufficient to admit a mixt. of strongly fluctuating dipole moments. These modify the elec. susceptibility and through this the quantum interference pattern in the presence of an external elec. field. Detailed mol. dynamics simulations combined with d.-functional theory allow us to quantify the time-dependent structural reconfigurations and to predict the ensemble-averaged square of the dipole moment which is found to be in good agreement with the interferometric result. The expt. thus opens a different perspective on matter wave interferometry, as we demonstrate here that it is possible to collect structural information about mols. even if they are delocalized over more than 100 times their own diam. [on SciFinder(R)]