Charles Marcus, University of Washington

Two-dimensional Josephson junction arrays exhibit complex energy landscapes when frustrated by magnetic flux and undergo topological (Kosterlitz-Thouless) and quantum (superconductor-insulator) phase transitions. They are a paradigm of complexity in a quantum system, one with several experimental knobs that can be tuned. In this talk, I’ll compare Josephson arrays on various lattices, with particular focus on the phenomenon of caging, where interference blocks the passage of Cooper pairs, which is related to a flat band condition.