M.I.T.

Title: Effects of Screening and Dissipation at the Superconductor-Insulator Transition

Abstract: We consider the Superconductor - Insulator transition in the presence of a nearby metallic plane, that is coupled to the Cooper pairs via the Coulomb interaction [1]. Besides being relevant to the experiments of reference [2], this provides a simple microscopic model within which the effects of screening and disspation on the (T=0) Superconductor-Insulator transition can be addressed. The physics resulting from the interplay of these effects will be discussed in this talk. In particular it will be argued that the transition may be controlled by a _line_ of fixed points. Evidence for this from a double epsilon expansion on a model with particle-hole symmetric disorder will be presented. A similar fixed line could arise for the Quantum Hall plateau transition in the presence of a ground plane; experimental implications for Josephson junction arrays and Quantum Hall systems will be discussed.

[1] A.V., J.E. Moore, T. Senthil cond-mat/0209109
[2] A.J. Rimberg et al. PRL 78, 2632 (1997).