Roton-roton crossover in strongly correlated dipolar Bose-Einstein condensates.

Manifestations of the Roton in Dipolar Bose-Einstein Condensates

Effective dipole-dipole interactions in multilayered dipolar Bose-Einstein condensates

We propose a two-dimensional model for a multilayer stack of dipolar Bose-Einstein condensates formed by a strong optical lattice. We derive effective intraand interlayer dipole-dipole interaction potentials and provide simple analytical approximations for a given number of lattice sites at arbitrary polarization. We find that the interlayer dipole-dipole interaction changes the transverse aspe...

Angular collapse of dipolar Bose-Einstein condensates

We explore the structure and dynamics of dipolar Bose-Einstein condensates DBECs near their threshold for instability. Near this threshold a DBEC may exhibit nontrivial biconcave density distributions, which are associated with instability against collapse into “angular roton” modes. Here we discuss experimental signatures of these features. In the first, we infer local collapse of the DBEC fro...

Three-dimensional roton excitations and supersolid formation in Rydberg-excited Bose-Einstein condensates.

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 spac...

Manifestations of the roton mode in dipolar Bose-Einstein condensates.

We investigate the structure of trapped Bose-Einstein condensates (BECs) with long-range anisotropic dipolar interactions. We find that a small perturbation in the trapping potential can lead to dramatic changes in the condensate's density profile for sufficiently large dipolar interaction strengths and trap aspect ratios. By employing perturbation theory, we relate these oscillations to a prev...