The breakdown of Fermi-liquid theory in systems of reduced dimensionality or with sufficiently strong interactions is a subject of considerable current interest. Phenomena such as the Mott-Hubbard metal-insulator transition, high-temperature superconductivity, and the fractional quantum Hall effect can not be accounted for within independent-electron models or standard perturbation theory, and have lead to a renaissance in theories of strongly-correlated electrons. Such correlation effects can be treated rigorously in one-dimesional systems, and in quasi-zero-dimensional systems, two major focuses of our research.
