title: Three-dimensional roton excitations and supersolid formation in Rydberg-excited Bose-Einstein condensates.
abstract: We study the behavior of a Bose-Einstein condensate in which atoms are weakly coupled to a highly excited Rydberg state. Since the latter have very strong van der Waals interactions, this coupling induces effective, nonlocal interactions between the dressed ground state atoms, which, opposed to dipolar interactions, are isotropically repulsive. Yet, one finds partial attraction in momentum space, giving rise to a roton-maxon excitation spectrum and a transition to a supersolid state in three-dimensional condensates. A detailed analysis of decoherence and loss mechanisms suggests that these phenomena are observable with current experimental capabilities.
authors.affiliation: Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Henkel
authors.forename: R
authors.initials: R
authors.lastname: Nath
authors.forename: T
authors.initials: T
authors.lastname: Pohl