Title

Many-body interactions between atoms and photons and their connections to condensed matter systems

Date of Completion

January 2007

Keywords

Physics, Condensed Matter|Physics, Atomic|Physics, Radiation

Degree

Ph.D.

Abstract

We first study effects of collective states (CS) in both superradiant and electromagnetically induced transparent (EIT) systems. For superradiance, we incorporate cooperative effects into a two-atom master equation, which results in a superradiant decay time close to the experimental data. Additionally, we identify the role of collectivity in Raman superradiance in a Bose-Einstein condensate (BEC). As an application of CS to quantum information, we study the feasibility of EIT in semiconductors, a flexible multiple beam splitter for generating entangled single photons, and effect of diffusion of the stored coherence. ^ Second, we show that transverse momentum distribution may improve the phase resolution of an atomic interferometer. The improvement is due to the fact that the transit time for the transverse momentum states is a constant. ^ Third, atom and molecule currents in a Fermi gas in the neighborhood of a Feshbach resonance are studied in a one-dimensional optical ring lattice by directly diagonalizing small models. A rotational analogy of flux quantization is used to show that a fraction of the current is carried by particles with twice the mass of an atom, which suggests pairing and superfluidity of fermions. ^