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Using the non-equilibrium Green function method, we study the Andreev reflection in a Y-shaped graphene-superconductor device by tight-binding model. Considering both the zigzag and armchair terminals, we confirm that the zigzag terminals…

Mesoscale and Nanoscale Physics · Physics 2018-07-11 Chao Wang , Youlian Zou , Juntao Song , Yu-Xian Li

We evaluate the differential conductance measured in a scanning tunneling microscopy (STM) setting at arbitrary electron transmission between an STM tip and a two-dimensional (2D) superconductor with arbitrary gap structure. Our analytical…

Superconductivity · Physics 2023-05-30 P. O. Sukhachov , Felix von Oppen , L. I. Glazman

The accurate and proper form of electron-hole excitations and corresponding Dirac-like spinors of monolayer molybdenum disulfide superconductor are exactly obtained. Andreev reflection and resulting subgap conductance in a $MoS_2$-based…

Mesoscale and Nanoscale Physics · Physics 2017-02-01 H. Goudarzi , M. Khezerlou , S. F. Ebadzadeh

We study Andreev reflection in graphene nanoribbon/superconductor hybrid junctions. By using a tight-binding approach and the scattering formalism we show that finite-size effects lead to notable differences with respect to the bulk…

Mesoscale and Nanoscale Physics · Physics 2009-03-28 Diego Rainis , Fabio Taddei , Fabrizio Dolcini , Marco Polini , Rosario Fazio

We study Andreev reflection in normal metal-superconductor junctions by using an extended Blonder-Tinkham-Klapwijk model combined with transport calculations based on density functional theory. Starting from a parameter-free description of…

Mesoscale and Nanoscale Physics · Physics 2014-10-28 Awadhesh Narayan , Ivan Rungger , Stefano Sanvito

The Andreev reflection of narrow ferromagnet/superconductor point contacts is theoretically studied. We show that the conductance quantization depends on whether the contact region is superconducting or ferromagnetic as well as on the…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Keiichirou Kikuchi , Hiroshi Imamura , Saburo Takahashi , Sadamichi Maekawa

Coherent charge transport along ballistic paths can be introduced into graphene by Andreev reflection, for which an electron reflects from a superconducting contact as a hole, while a Cooper pair is transmitted. We use a liquid-helium…

Mesoscale and Nanoscale Physics · Physics 2020-08-26 S. Bhandari , G. -H. Lee , K. Watanabe , T. Taniguchi , P. Kim , R. M. Westervelt

Sub-gap conductance at a large area junction with a rough interface of a ferromagnet and a high-T$_{C}$ superconductor is superimposed by multiple peaks which is not expected from an ideal point contact Andreev reflection process. We…

Superconductivity · Physics 2009-03-25 N. Ghosh , H. Schmidt , M. Grundmann

In a graphene-based Josephson junction, the Andreev reflection can become specular which gives rise to propagating Andreev modes. These propagating Andreev modes are essentially charge neutral and therefore they transfer energy but not…

Superconductivity · Physics 2020-07-01 Zahra Faraei , S. A. Jafari

Andreev reflection in a monolayer molybdenum disulfide superconducting-normal (S/N) hybrid junction is investigated. We find, by using a modified-Dirac Hamiltonian and the scattering formalism, that the perfect Andreev reflection happens at…

Mesoscale and Nanoscale Physics · Physics 2014-01-16 Leyla Majidi , Habib Rostami , Reza Asgari

We theoretically study the Andreev reflection (AR) in AA-stacked bilayer graphene/superconductor (AABG/SC) junction. AABG has a linear gapless energy band with two shifted Dirac cones and the electronic states are described by the cone…

Mesoscale and Nanoscale Physics · Physics 2025-09-08 Wei-Tao Lu , Qing-Feng Sun

We numerically investigate Andreev reflection in a graphene ring with one normal conducting and one superconducting lead by solving the Bogoliubov--de Gennes equation within the Landauer-B\"uttiker formalism. By tuning chemical potential…

Mesoscale and Nanoscale Physics · Physics 2012-03-19 Jörg Schelter , Björn Trauzettel , Patrik Recher

A ballistic strip of graphene (width W>> length L) connecting two normal metal contacts is known to have a minimum conductivity of 4e^{2}/pi h at the Dirac point of charge neutrality. We calculate what happens if one of the two contacts…

Mesoscale and Nanoscale Physics · Physics 2013-07-09 A. R. Akhmerov , C. W. J. Beenakker

We investigate the Andreev tunneling and Josephson current in graphene irradiated with high-frequency linearly polarized light. The corresponding stroboscopic dynamics can be solved using Floquet mechanism which results in an effective…

Strongly Correlated Electrons · Physics 2018-06-21 Debabrata Sinha , Satyaki Kar

Andreev-reflection spectroscopy of elemental superconductors in contact with non-magnetic normal metals reveals that the strength of normal-reflection varies only slightly. This observation imposes strong constrictions on the three possible…

Mesoscale and Nanoscale Physics · Physics 2015-06-22 K. Gloos , E. Tuuli

Andreev reflection-where an electron in a normal metal backscatters off a superconductor into a hole-forms the basis of low energy transport through superconducting junctions. Andreev reflection in confined regions gives rise to discrete…

We investigate the Andreev reflection process in high-mobility HgTe/CdTe quantum wells. We find that Andreev conductance probes the dynamics of massive 2+1 Dirac fermions, and that both specular Andreev reflection and retroreflection can be…

Mesoscale and Nanoscale Physics · Physics 2015-03-17 M. Guigou , J. Cayssol

In view of the recent progress in experiments on charge transport through various Josephson junctions made out of graphene, we have made a careful comparison between the theory and some of the available experimental results. Within the…

Superconductivity · Physics 2023-05-12 Shahrukh Salim , Rahul Marathe , Sankalpa Ghosh

Based on the BTK theory, we investigate the tunneling conductance in a uniaxially strained graphene-based normal metal (NG)/ barrier (I)/superconductor (SG) junctions. In the present model, we assume that depositing the conventional…

Mesoscale and Nanoscale Physics · Physics 2011-08-12 Bumned Soodchomshom

In this article, we study the transport properties of Graphene-Superconductor-Graphene (GSG) heterojunction where the superconducting region is created in the middle of a graphene sheet, as contrasted to widely studied transport properties…

Mesoscale and Nanoscale Physics · Physics 2023-11-16 Shahrukh Salim , Rahul Marathe , Sankalpa Ghosh