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The transport properties of a ferromagnet-superconductor (FS) junction are studied in a scattering formulation. Andreev reflection at the FS interface is strongly affected by the exchange interaction in the ferromagnet. The conductance G_FS…

Condensed Matter · Physics 2017-12-07 M. J. M. de Jong , C. W. J. Beenakker

We consider theoretically a Josephson junction with a superconducting critical current density which has a random sign along the junction's surface. We show that the ground state of the junction corresponds to the phase difference equal to…

Disordered Systems and Neural Networks · Physics 2009-10-31 A. Zyuzin , B. Spivak

Andreev bound states are superpositions of electrons and holes in a metal that form by coherent reflection from a superconductor. When the length of the superconductor is comparable to the superconducting coherence length, Andreev bound…

Mesoscale and Nanoscale Physics · Physics 2025-08-19 Anders Enevold Dahl , Andrea Maiani , Max Geier , Javad Shabani , Karsten Flensberg

Graphene-based Josephson junctions provide a novel platform for studying the proximity effect due to graphene's unique electronic spectrum and the possibility to tune junction properties by gate voltage. Here we describe graphene junctions…

The theory of Andreev conductance is formulated for junctions involving normal metals (N) and multiband superconductors (S) and applied to the case of superconductors with nodeless extended $s_{\pm}$-wave order parameter symmetry, as…

Superconductivity · Physics 2015-05-13 A. A. Golubov , A. Brinkman , O. V. Dolgov , I. I. Mazin , Y. Tanaka

We theoretically demonstrate unusual features of superconducting proximity effect in gapped graphene which presents a pseudospin symmetry-broken ferromagnet with a net pseudomagnetization. We find that the presence of a band gap makes the…

Mesoscale and Nanoscale Physics · Physics 2015-06-11 Leyla Majidi , Malek Zareyan

Electrical properties of Josephson junctions Nb/FeSi/Nb with superconductor/ferromagnet (S/F)interfaces are presented. Due to Andreev reflection the nearly exact quadruple enhancement of the tunnel junction differential conductance compared…

Superconductivity · Physics 2007-05-23 O. Vavra , S. Gazi , I. Vavra , G. Radnoczi , V. V. Moshchalkov , J. Derer , E. Kovacova

In tunneling spectroscopy studies of ferromagnet/superconductor (F/S) junctions, the effects of spin polarization, Fermi wavevector mismatch (FWM) between the F and S regions, and interfacial resistance play a crucial role. We study the low…

Superconductivity · Physics 2009-10-31 Igor Zutic , Oriol T. Valls

Electrons incident from a normal metal onto a superconductor are reflected back as holes - a process called Andreev reflection. In a normal metal where the Fermi energy is much larger than a typical superconducting gap, the reflected hole…

Mesoscale and Nanoscale Physics · Physics 2016-08-04 D. K. Efetov , L. Wang , C. Handschin , K. B. Efetov , J. Shuang , R. Cava , T. Taniguchi , K. Watanabe , J. Hone , C. R. Dean , P. Kim

We derive a microscopic effective action for superconducting contacts with arbitrary transmission distribution of conducting channels. Provided fluctuations of the Josephson phase remain sufficiently small our formalism allows to fully…

Superconductivity · Physics 2015-05-18 A. V. Galaktionov , A. D. Zaikin

We study the microscopic structure of the Josephson current in a single-mode tunnel junction with a wide quasiclassical tunnel barrier. In such a junction each Andreev bound state carries a current of magnitude proportional to the {\em…

Condensed Matter · Physics 2009-10-28 G. Wendin , V. S. Shumeiko

The response of superconductor-normal-metal-superconductor junctions to magnetic field is complicated and non-universal because all trajectories contributing to supercurrent have a different effective area, and therefore acquire arbitrary…

Mesoscale and Nanoscale Physics · Physics 2018-10-11 Muhammad Irfan , Anton R. Akhmerov

We consider Andreev reflection in a two dimensional junction between a normal metal and a heavy fermion superconductor in the Fulde-Ferrell (FF) type of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state. We assume s-wave symmetry of the…

Superconductivity · Physics 2011-03-10 J. Kaczmarczyk , M. Sadzikowski , J. Spałek

We study the Josephson effect in $s_{\pm}/I/s_{\pm}$ junctions made by two bands reversed sign s-wave ($s_{\pm}$) superconductive materials. We derive an equation providing the bound Andreev energy states parameterized by the band ratio…

Superconductivity · Physics 2013-01-30 C. Nappi , S. De Nicola , M. Adamo , E. Sarnelli

In this paper we address several new developments in the theory of dc Josephson effect in superconducting weak links. We analyze an interplay between quantum interference effects and Andreev reflection in SNS nanojunctions with insulating…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Andrei D. Zaikin

We study theoretically the Josephson effect between two time-reversal two-band superconductors, where we assume the equal-time spin-singlet $s$-wave pair potential in each conduction band. %as well as the band asymmetry and the band…

Superconductivity · Physics 2020-05-13 Akihiro Sasaki , Satoshi Ikegaya , Tetsuro Habe , Alexander A. Golubov , Yasuhiro Asano

We study nonequilibrium effects in current transport through voltage biased tunnel junction with long diffusive superconducting leads at low applied voltage, $eV \ll 2\Delta$, and finite temperatures. Due to a small value of the Josephson…

Superconductivity · Physics 2011-01-11 E. V. Bezuglyi , A. S. Vasenko , V. S. Shumeiko , G. Wendin

The tunneling spectrum of an electron and a hole in metal-superconductor-metal junctions is computed using the Blonder-Tinkham-Klapwijk theory. The incident and the outgoing currents finally balance each other by an interface charge inside…

Superconductivity · Physics 2014-08-20 W. LiMing , J. J. Ouyang , Liangbin Hu

It is shown that the low energy spectrum of mesoscopic superconductors coupled by Josephson interaction can be probed by two-electron tunneling from a normal electrode. The Andreev reflection in the NS junction of a…

Condensed Matter · Physics 2009-10-22 F. W. J. Hekking , L. I. Glazman , Gerd Schoen

The stationnary Josephson effect in a clean Superconductor-Ferromagnet-Superconductor junction is revisited for arbitrarily large spin polarizations. The quasiclassical calculation of the supercurrent assumes that the Andreev reflection is…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 J. Cayssol , G. Montambaux