Theory of the Josephson effect in unconventional superconducting junctions with diffusive barriers
نویسندگان
چکیده
We study theoretically the Josephson effect in junctions based on unconventional superconductors with diffusive barriers, using the quasiclassical Green’s function formalism. Generalized boundary conditions at junction interfaces applicable to unconventional superconductors are derived by calculating a matrix current within the circuit transport theory. Applying these boundary conditions, we have calculated the Josephson current in structures with various pairing symmetries. A number of predictions are made: a nonmonotonic temperature dependence in d-wave superconductor/diffusive normal metal/d-wave superconductor D/DN/D junctions, b anomalous current-phase relations in p-wave superconductor/diffusive normal metal/p-wave superconductor P/DN/P junctions, c second harmonics in D/DN/D and P/DN/P junctions, d a double-peak structure of the critical current in D/DF/D junctions, and e enhanced Josephson current by the exchange field in S/DF/P junctions. We have also investigated peculiarities of the Josephson coupling in D/DF/D, P/DF/P, and S/DF/P junctions. An oscillatory behavior of the supercurrent and the second harmonics in the current-phase relation is studied as a function of the length of the diffusive ferromagnet.
منابع مشابه
Quasiclassical Green’s function theory of the Josephson effect in chiral p-wave superconductor/diffusive normal metal/chiral p-wave superconductor junctions
We study the Josephson effect in chiral p-wave superconductor/diffusive normal metal DN /chiral p-wave superconductor CP/DN/CP junctions using quasiclassical Green’s function formalism with proper boundary conditions. The px+ ipy-wave symmetry of superconducting order parameter is chosen which is believed to be the pairing state in Sr2RuO4. We show that the superconducting pair amplitude induce...
متن کاملJosephson Current For a Graphene Nanoribbon Using a Lattice Model
A tight binding approach based on the Bogoliubov-de Gennes approach has been used to calculate the DC Josephson current for a lattice model for S-GNR-S junctions , for short junctions with respect to superconducting coherence length. We calculate the phase, length, width and chemical potential dependence at the Josephson junction and discuss the similarities and differences with regard to the t...
متن کاملUnconventional Josephson effect in hybrid superconductor-topological insulator devices.
We report on transport properties of Josephson junctions in hybrid superconducting-topological insulator devices, which show two striking departures from the common Josephson junction behavior: a characteristic energy that scales inversely with the width of the junction, and a low characteristic magnetic field for suppressing supercurrent. To explain these effects, we propose a phenomenological...
متن کاملJosephson current and multiple Andreev reflections in graphene SNS junctions
The Josephson effect and superconducting proximity effect were observed in superconductor-graphenesuperconductor SGS Josephson junctions with coherence lengths comparable to the distance between the superconducting leads. By comparing the measured gate dependence of the proximity induced subgap features multiple Andreev reflections and of the supercurrent to theoretical predictions, we find tha...
متن کاملTowards The Determination of Properties of the Unconventional Josephson Junction Made by Putting Non-Superconducting Strip on the Top of Superconducting Strip
We present the theoretical approach to study the unconventional Josephson junction (uJJ) made by putting the non-superconducting strip on the top of superconducting strip. We work in the framework of the Ginzburg-Landau, Bogoliubov de Gennes and Usadel equations. Then we solve the non-linear partial differential equations numerically for few simple cases. We review the similarities and new aspe...
متن کامل