Optical trapping as a viable means of exploring the physics of ultracold dilute atomic gases has revealed a new spectrum of physical phenomena. In particular, macroscopic and sudden occupation of the ground state below a critical temperature---a phenomenon known as Bose-Einstein condensation---has become an even richer system for the study of quantum mechanics, ultracold collisions, and many-body physics in general. Optical trapping liberates the spin degree of the BEC, making the order parameter vectorial ('spinor BEC'), as opposed to the scalar order of traditional magnetically trapped condensates.

Bose-Einstein condensation (BEC) is a phenomenon in which identical bosons occupy the same quantum state below a certain critical temperature. A hallmark of BEC is the coherence between particles every particle shares the same quantum wavefunction and phase. This coherence has been demonstrated for the external (motional) degrees of freedom of the atomic condensates by interfering two condensates. In this thesis, the coherence is shown to extend to the internal spin degrees of freedom of a spin-1 Bose gas evidenced by the observed coherent and reversible spin-changing collisions. The observed coherent dynamics are analogous to Josephson oscillations in weakly connected superconductors and represent a type of matter-wave four-wave mixing. Control of the coherent evolution of the system using magnetic fields is also demonstrated. The studies on spinor condensates begin by creating spinor condensates directly using all-optical approaches that were first developed in our laboratory. All-optical formation of Bose-Einstein condensates (BEC) in 1D optical lattice and single focus trap geometries are developed and presented. These techniques offer considerable flexibility and speed compared to magnetic trap approaches, and the trapping potential can be essentially spin-independent and are ideally suited for studying spinor condensates. Using condensates with well-defined initial non-equilibrium spin configuration, spin mixing of F = 1 and F = 2 spinor condensates of rubidium-87 atoms confined in an optical trap is observed. The equilibrium spin configuration in the F = 1 manifold confirms that 87Rb is ferromagnetic. The coherent spinor dynamics are demonstrated by initiating spin mixing deterministically with a non-stationary spin population configuration. Finally, the interplay between the coherent spin mixing and spatial dynamics in spin-1 condensates with ferromagnetic interactions is investigated.

Proceedings of the International School of Quantum Electronics 27th course on Bose Einstein Condensates and Atom Lasers, October 19-24, 1999, Erice, Italy. Since the experimental demonstration of Bose Einstein Condensation in dilute atomic gases there has been an explosion of interest in the properties of this novel macroscopic quantum system. The book covers the methods used to produce these new samples of coherent atoms, their manipulation and the study of their properties. Emphasis is given to the anticipated development of new types of sources, which more and more resemble traditional types of lasers. Because of recent new applications and increasing demand for lasers, sensors and associated instrumentation, the chapters also cover current developments in the basic techniques, materials and applications in the field of the generation of coherent atoms.

This book covers the fundamentals of and new developments in gaseous Bose-Einstein condensation. It begins with a review of fundamental concepts and theorems, and introduces basic theories describing Bose-Einstein condensation (BEC). It then discusses some recent topics such as fast-rotating BEC, spinor and dipolar BEC, low-dimensional BEC, balanced and imbalanced fermionic superfluidity including BCS-BEC crossover and unitary gas, and p-wave superfluidity.

Bose-Einstein condensation of dilute gases is an exciting new field of interdisciplinary physics. The eight chapters in this volume introduce its theoretical and experimental foundations. The authors are lucid expositors who have also made outstanding contributions to the field. They include theorists Tony Leggett, Allan Griffin and Keith Burnett, and Nobel-Prize-winning experimentalist Bill Phillips. In addition to the introductory material, there are articles treating topics at the forefront of research, such as experimental quantum phase engineering of condensates, the “superchemistry” of interacting atomic and molecular condensates, and atom laser theory.