Mesoscopic phenomena in Bose-Einstein systems: Persistent currents, population oscillations, and quantal phases

Mesoscopic phenomena—including population oscillations and persistent currents driven by quantal phases—are explored theoretically in the context of multiply connected Bose-Einstein systems composed of trapped alkali-metal gas atoms. These atomic phenomena are bosonic analogs of electronic persistent currents in normal metals and Little-Parks oscillations in superconductors. Differences between oscillatory phenomena due to quantal phases in Bose-Einstein systems and in conventional superconductors are discussed, particularly with regard to their potential for discriminating between the standard BCS scenario and the Bose-Einstein condensation of preformed pairs scenario for the superconducting transition in high-temperature superconductors.