Stuttgart 2012 – wissenschaftliches Programm
A 20.1: Hauptvortrag
Dienstag, 13. März 2012, 14:00–14:30, V47.01
Ultralong-range Rydberg molecules — •Thomas Pohl — MPI for the Physics of Complex Systems, Dresden, Germany
Ultralong-range Rydberg molecules represent an extreme and peculiar example of chemical binding, where a ground state atom is bound inside the electronic wave function of a highly excited Rydberg atom. Owing to their large bond length of several thousand Bohr radii, these molecules - first produced in 2009  - exhibit several unusual properties, some of which will be discussed in this talk.
Following a simplified discussion of the basic interaction mechanisms, I will describe more sophisticated calculations, which reveal, yet, another new binding mechanism based on internal quantum reflection . Good agreement with experiments on ultracold Rubidium molecules, gives strong indication that the predicted molecular states indeed provide a manifestation of such elementary quantum phenomena. A close look at small-electric field effects uncovers the existence of a sizable molecular electric dipole moment , which comes as a surprise for homo-nuclear molecules.
Besides being of fundamental interest, such exotic molecules turn out to be also of relevance to other Rydberg-atom settings. In order to illustrate this point, I will consider their collective excitation dynamics in mesoscopic ultracold gases and discuss possible implications for ensemble-based quantum information/optics applications.
 V. Bendkowsky et al., Nature (London) 458, 1005 (2009)
 V. Bendkowsky et al., Phys. Rev. Lett. 105, 163201 (2010)
 W. Li et al., Science 334, 1110 (2011)