Analytical and numerical research will be undertaken on quantum coherence, charge fluctuation and transport phenomena in mesoscopic structures. The initial focus of this research will be on a comprehensive theory of mesoscopic persistent currents in isolated rings, macroscopic quantum tunneling in ultranarrow wires, and related static and dynamic mesoscopic phenomena. The goal of this work is the elucidation of the unusual quantum coherence and statistical mechanical effects that occur in the electronic, thermal and mechanical properties of submicrometer-sized structures. Crossover phenomena that occur in nanometer-scale superconducting rings and wires will also be studies. %%% Mesoscopic physics occurs at the boundary between the classical and quantum regimes. For instance, as the size of an electronic device decreases, a region will be reached where the classical or semi- classical description which modeled the behavior of the device will no longer apply. Quantum effects come into play. Clearly, an understanding of these effects has an important impact on solid state electronics as the size of devices continues to decrease. On the other hand, these mesoscopic effects reveal fundamental properties of condensed matter systems and can themselves be used as bases for devices.
