2013/12/02 by Long He, Jian Sun, He, Long +3
Physics and Astronomy · #FOS: Physical sciences #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Superconductivity (cond-mat.supr-con) #Surface and Thin Film Phenomena
paper · pdf · doi:10.48550/arxiv.1312.0367
openalex publication_date 2013/12/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study the superconductor-insulator transition (SIT) in d-wave superconducting ultrathin films. By means of the kernel polynomial method, the Bogoliubov-de Gennes equations are solved for square lattices with up to 360× 360 unit cells self-consistently, making it possible to observe fully the nanoscale spatial fluctuations of the superconducting order parameters and discriminate accurately the localized quasiparticle states from the extended ones by the lattice-size scaling of the generalized inverse participation ratio. It is shown that Anderson localization can not entirely inhibit the occurrence of the local superconductivity in strongly-disordered d-wave superconductors. Separated by an insulating 'sea' completely, a few isolated superconducting 'islands' with significant enhancement of the local superconducting order parameters can survive across the SIT. The disorder-driven SIT, therefore, is a transition from a d-wave superconductor to a Bose insulator which consists of localized Cooper pairs. Unlike an s-wave superconductor which presents a robust single-particle gap across the SIT, the optical conductivity of a d-wave superconductor reveals a gapless insulating phase, where the SIT can be detected by observing the disappearance of the Drude weight with the increasing disorder.