Mathematics Research Centre, Queen Mary Department of Mathematics, Brunel University

"RANDOM MATRICES AND RELATED TOPICS"

Monthly Colloquia

Date and time: 8 March 2002, 16:30

Location: Room B2 or 513, School of Mathematical Sciences, Queen Mary

Speaker: Dr. B.D. Simons (Cambridge)

"Instantons and Localised Sub-gap States in Disordered Superconductors"

Abstract: The spectral properties of random Schrodinger operators are heavily influenced by mechanisms of quantum phase coherence. Such effects are recorded experimentally in characteristic fluctuation and localisation phenomena. Recently, attempts have been made to explore the impact of phase coherence effects in weakly disordered superconducting structures. In this talk, show how optimal fluctuations of a random impurity potential provide a generic mechanism for the spontaneous nucleation of localised states which collapse the quasi-particle energy gap. We discuss the implications of this general field theoretic scheme for the properties of other physical systems which exhibit a gap structure.