The presence of quantized vortices and a high level of control over trap geometries and other system parameters make dilute-gas Bose-Einstein condensates (BECs) a natural environment for studies of vortex dynamics and quantum turbulence in superfluids, primary interests of the BEC group at the University of Arizona. Such research may lead to deeper understanding of the nature of quantum fluid dynamics and far-from-equilbrium phenomena.Despite the importance of quantized vortex dynamics in the fields of superfluidity, superconductivity and quantum turbulence, direct imaging of vortices in trapped BECs remains a significant technical challenge. This is primarily due to the small size of the vortex core in a trapped gas, which is typically a few hundred nanometers in diameter. In this dissertation I present the design and construction of a new ^87Rb BEC apparatus with the goal of studying vortex dynamics in trapped BECs. The heart of the apparatus is a compact vacuum chamber with a custom, all-glass science cell designed to accommodate the use of commercial high-numerical-aperture microscope objectives for in situ imaging of vortices.The designs for the new system are, in part, based on prior work in our group on in situ imaging of vortices. Here I review aspects of our prior work and discuss some of the successes and limitations that are relevant to the new apparatus. The bulk of the thesis is used to described the major subsystems of the new apparatus which include the vacuum chamber, the laser systems, the magnetic transfer system and the final magnetic trap for the atoms. Finally, I demonstrate the creation of a BEC of ~2x10^6 ^87Rb atoms in our new system and show that the BEC can be transferred into a weak, spherical, magnetic trap with a well defined magnetic field axis that may be useful for future vortex imaging studies.
The thesis presented has three components: experiments with artificial vector potentials, a new atom-chip apparatus designed and built for light-less fictitious gauge fields, and an imaging experiment. First, we introduce experiments with light-induced vector potentials using two-photon Raman coupling to simulate charged particles using charge neutral Bose-Einstein condensates (BECs). Depending on the spatial and temporal properties of the engineered vector potential, it is possible for ultracold atoms to experience different variants of an effective Lorenz force such as; magnetic fields, electric fields, and spin-orbit coupling, via coupling between an atom's internal spin and its linear momentum. In this context, we discuss the main focus of this thesis, the design and construction of an atom-chip apparatus for
87Rb BECs for experiments with light-less artificial gauge fields. Eliminating the source of heating due to spontaneous emission will open new paths to explore artificial gauge fields in alkali fermions and will be a step towards the realization of simulated topological insulators using ultracold atoms. Finally, we will describe in detail an imaging experiment performed on this new apparatus, the reconstruction of the two-dimensional column density of a BEC using multiple defocused images taken simultaneously.