title: Phase fluctuations in a strongly disordered s-wave NbN superconductor close to the metal-insulator transition.
abstract: We explore the role of phase fluctuations in a three-dimensional s-wave superconductor, NbN, as we approach the critical disorder for destruction of the superconducting state. Close to critical disorder, we observe a finite gap in the electronic spectrum which persists at temperatures well above T(c). The superfluid density is strongly suppressed at low temperatures and evolves towards a linear-T variation at higher temperatures. These observations provide strong evidence that phase fluctuations play a central role in the formation of a pseudogap state in a disordered s-wave superconductor.
authors.affiliation: Tata Institute of Fundamental Research, Mumbai, India.
authors.forename: Mintu
authors.initials: M
authors.lastname: Mondal
authors.forename: Anand
authors.initials: A
authors.lastname: Kamlapure
authors.forename: Madhavi
authors.initials: M
authors.lastname: Chand
authors.forename: Garima
authors.initials: G
authors.lastname: Saraswat
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Kumar
authors.forename: John
authors.initials: J
authors.lastname: Jesudasan
authors.forename: L
authors.initials: L
authors.lastname: Benfatto
authors.forename: Vikram
authors.initials: V
authors.lastname: Tripathi
authors.forename: Pratap
authors.initials: P
authors.lastname: Raychaudhuri