Light-induced dipole–dipole interactions

R Löw, R Gati, J Stuhler +1 more

We theoretically investigate the mechanical effect of the light-induced dipole-dipole interaction potential on the atoms in a Bose-Einstein condensate. We present numerical calculations on the magnitude and shape of the induced potentials for different experimentally accessible geometries. It is shown that the mechanical effect can be distinguished from the effect of incoherent scattering for an experimentally feasible setting.

H. H. Jen, Guin-Dar Lin, Ying-Cheng Chen

Resonant dipole-dipole interaction (RDDI) emerges in strong light-matter interacting systems, which leads to many fascinating phenomena such as cooperative light scattering and collective radiation. Here, we theoretically investigate the role of RDDI in electromagnetically induced transparency (EIT). The resonant dipole-dipole interactions manifest themselves in the cooperative spontaneous emission of the probe light transition, which give rise a broadened linewidth and associated collective frequency shift. This cooperative linewidth originates from the nonlocal and long-range RDDI, which can be determined by the atomic density, optical depth, and macroscopic length scales of the atomic ensemble. We present the finding that EIT spectroscopy essentially demonstrates all-order multiple scattering of RDDI. Furthermore, we find that the EIT transparency window becomes narrower as the cooperative linewidth increases, which essentially reduces the storage efficiency of slow light as an EIT-based quantum memory application.

Eli Yablonovitch

Nicolas Cherroret, Dominique Delande, Bart A. van Tiggelen

We develop a perturbative treatment of induced dipole-dipole interactions in the diffusive transport of electromagnetic waves through disordered atomic clouds. The approach is exact at order 2 in the atomic density and accounts for the vector character of light. It is applied to the calculations of the electromagnetic energy stored in the atomic cloud, which modifies the energy transport velocity, and of the light scattering and transport mean free paths. Results are compared to those obtained from a purely scalar model for light.

Gavin K. Brennen