Induced dipole-dipole interactions in light diffusion from point dipoles

Observation of suppression of light scattering induced by dipole-dipole interactions in a cold-atom ensemble.

We study the emergence of collective scattering in the presence of dipole-dipole interactions when we illuminate a cold cloud of rubidium atoms with a near-resonant and weak intensity laser. The size of the atomic sample is comparable to the wavelength of light. When we gradually increase the number of atoms from 1 to ~450, we observe a broadening of the line, a small redshift and, consistently...

Dipole-dipole interactions in nanoparticle superlattices.

Nanoparticles often self-assemble into hexagonal-close-packed (hcp) structures although it is predicted to be less stable than face-centered-cubic (fcc) packing in hard-sphere models. In addition to close-packed fcc and hcp superlattices, we observe formation of nonclose-packed simple-hexagonal (sh) superlattices of nearly spherical PbS, PbSe, and gamma-Fe2O3 nanocrystals. This surprisingly ric...

Dipole - Dipole Interactions of Charged - Magnetic Grains

Dipole Interactions in Nanosystems

The dipole-dipole interaction influences nanoscopic matter by fixing the patterns of permanent, displacive, and induced dipole moments, subject to constraints of molecular size and other short range interactions. Prediction of these arrangements is a challenging problem. The eigenvector of maximum eigenvalue of the dipole-dipole interaction matrix can provide insights and sometimes a complete s...

Diffusion measurements free of motion artifacts using intermolecular dipole-dipole interactions.

Diffusion encoding, or diffusion weighting, is commonly achieved by applying a pair of balanced pulsed-field gradients during spin evolution. An alternative way to obtain diffusion measurements is to select dipolar correlation distances using the distant dipolar field (DDF) in systems with abundant spin density, such as water in tissues. Diffusion weighting using this effect is unique in that t...