Special CPM Seminar

Emergent granularity and the superconductor-insulator transition: Present Status and Open Questions

Nandini Trivedi

Ohio State University

In an interesting interplay of amplitude and phase fluctuations across the disorder-driven superconductor-insulator transition, we show that the single particle gap survives across the transition, but coherence peaks exist only in the superconductor. Even for a BCS superconductor, the state above Tc in the presence of disorder is not normal but has a characteristic pseudogap. And surprisingly, the insulator has a two-particle gap scale that vanishes at the transition, despite a robust single-particle gap. Our predictions are testable with scanning probe experiments.