2011/01/28 by Shawna Hollen, S. M. Hollen, Hung Q. Nguyen +10
Physics and Astronomy · #Advanced Condensed Matter Physics #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.84.064528
published as Phys. Rev. B 84, 064528 (2011) · 4 pages, 3 figures, 1 supplemental page with 1 supplemental figure
arxiv created 2011/01/28 · openalex publication_date 2011/08/25 · arxiv updated 2013/01/28 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Ultrathin films near the quantum insulator-superconductor transition (IST) can exhibit Cooper-pair transport in their insulating state. This Cooper-pair insulator (CPI) state is achieved in amorphous Bi films evaporated onto substrates with a topography varying on lengths slightly greater than the superconducting coherence length. We present evidence that this topography induces film thickness and corresponding superconducting coupling constant variations that promote Cooper-pair island formation. Analyses of many thickness-tuned ISTs show that weak links between superconducting islands dominate the transport. In particular, the IST occurs when the link resistance approaches the resistance quantum for pairs. These results support conjectures that the CPI is an inhomogeneous state of matter.