Regensburg 2013 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 6: Superconductivity: Tunnelling & Josephson Junctions

TT 6.12: Vortrag

Montag, 11. März 2013, 12:30–12:45, H18

Josephson supercurrent in a graphene-superconductor junction — •Esmaeel Sarvestani¹ and Seyed Akbar Jafari² — ¹Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany — ²Department of Physics, Sharif University of Technology, Tehran 11155-9161, Iran

Within the tunneling Hamiltonian formulation for the eight-component spinors, the Josephson critical supercurrent has been calculated in a planar superconductor-normal graphene-superconductor junction. Coupling between superconductor regions and graphene is taken into account by a tunneling Hamiltonian which contains two types of tunneling, intravalley and intervalley tunneling. Within the present tunneling approach, we find that the contributions of two kinds of tunneling to the critical supercurrent are completely separable. Therefore, it is possible to consider the effect of the intervalley tunnelings in the critical supercurrent. The incorporation of these type of processes into the tunneling Hamiltonian exposes a special feature of the graphene Josephson junctions. The effect of intervalley tunneling appears in the length dependence plot of critical current in the form of oscillations. We also present the results for temperature dependence of critical supercurrent and compare with experimental results and other theoretical calculations.