2008/03/25 by Annica M. Black‐Schaffer, Annica M. Black-Schaffer, Sebastian Doniach · 91 citations
Materials Science · Physics and Astronomy · #Coherence (philosophical gambling strategy) #Coherence length #Condensed matter physics #Conductor #Formalism (music) #Graphene #Graphene research and applications #Josephson effect #Materials science #Physics #Physics of Superconductivity and Magnetism #Pi Josephson junction #Quantum and electron transport phenomena #Quantum mechanics #Superconducting coherence length #Superconductivity #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.78.024504
published in Physical Review B 78(2) (American Physical Society) · 8 pages, 6 figures
arxiv created 2008/03/25 · openalex publication_date 2008/07/01 · arxiv updated 2010/10/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We use a tight-binding Bogoliubov--de Gennes (BdG) formalism to self-consistently calculate the proximity effect, Josephson current, and local density of states in ballistic graphene superconductor-normal conductor-superconductor (SNS) Josephson junctions. Both short and long junctions, with respect to the superconducting coherence length, are considered, as well as different doping levels of the graphene. We show that self-consistency does not notably change the current-phase relationship derived earlier for short junctions using the non-self-consistent Dirac--BdG formalism [M. Titov and C. W. J. Beenakker, Phys. Rev. B 74, 041401(R) (2006)] but predict a significantly increased critical current with a stronger junction-length dependence. In addition, we show that in junctions with no Fermi-level mismatch between the N and S regions, superconductivity persists even in the longest junctions we can investigate, indicating a diverging Ginzburg-Landau superconducting coherence length in the normal region.