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Related papers: The Anderson-Josephson quantum dot -- A theory per…

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We apply a Gutzwiller-like variational technique to study Josephson conduction across a quantum dot with an odd number of electrons connected to two superconducting leads. We show that, for small values of the superconducting gap, Kondo…

Strongly Correlated Electrons · Physics 2007-05-23 G. Campagnano , D. Giuliano , A. Tagliacozzo

We investigate the supercurrent through a quantum dot for the whole range of couplings using the numerical renormalization group method. We find that the Josephson current switches abruptly from a $\pi$- to a 0-phase as the coupling…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Mahn-Soo Choi , Minchul Lee , Kicheon Kang , W. Belzig

We consider a Hamiltonian model for a quantum dot which is placed between two superconducting leads with a constant bias imposed between these leads. Using the non-equilibrium Keldysh technique, we focus on the subgap current, where it is…

Mesoscale and Nanoscale Physics · Physics 2009-12-02 Thibaut Jonckheere , Alex Zazunov , K. Bayandin , Vitaly Shumeiko , Thierry Martin

We apply a Gutzwiller-like variational technique to study Josephson conduction across a quantum dot with an odd number of electrons connected to two superconducting leads. Our method projects out all states on the dot but the Kondo singlet…

Strongly Correlated Electrons · Physics 2009-11-10 Gabriele Campagnano , Domenico Giuliano , Adele Naddeo , Arturo Tagliacozzo

This paper studies the physics of junctions containing superconducting $(S)$ and normal $(N)$ leads weakly coupled to an Anderson impurity in the Kondo regime $(K)$. Special attention is devoted to the case where one of the leads is a…

Strongly Correlated Electrons · Physics 2009-11-07 T. Aono , A. Golub , Y. Avishai

The Josephson effect describes supercurrent flowing through a junction connecting two superconducting leads by a thin barrier [1]. This current is driven by a superconducting phase difference $\phi$ between the leads. In the presence of…

Mesoscale and Nanoscale Physics · Physics 2017-07-28 D. B. Szombati , S. Nadj-Perge , D. Car , S. R. Plissard , E. P. A. M. Bakkers , L. P. Kouwenhoven

The Josephson current through an Aharonov-Bohm (AB) interferometer, in which a quantum dot (QD) is situated on one arm and a magnetic flux $\Phi$ threads through the ring, has been investigated. With the existence of the magnetic flux, the…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Shu-guang Cheng , Yanxia Xing , X. C. Xie , Qing-feng Sun

We realize a hybrid superconductor-semiconductor transmon device in which the Josephson effect is controlled by a gate-defined quantum dot in an InAs/Al nanowire. Microwave spectroscopy of the transmon's transition spectrum allows us to…

We use a hybrid superconductor-semiconductor transmon device to perform spectroscopy of a quantum dot Josephson junction tuned to be in a spin-1/2 ground state with an unpaired quasiparticle. Due to spin-orbit coupling, we resolve two…

We study theoretically the Josephson current-phase relationship in a chaotic quantum dot coupled to superconductors by ballistic contacts. In this regime, strong proximity effect induces superconductivity in the quantum dot that leads to a…

Superconductivity · Physics 2018-06-27 Colin M. Whisler , Maxim G. Vavilov , Alex Levchenko

Electronic transport through nanostructures is greatly affected by the presence of superconducting leads. If the interface between the nanostructure and the superconductors is sufficiently transparent, a dissipationless current…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Pablo Jarillo-Herrero , Jorden A. van Dam , Leo P. Kouwenhoven

We investigate the Josephson current through a suspended carbon nanotube double quantum dot which, at sufficiently low temperatures, is characterized by the ground state of the electronic subsystem. Depending on parameters like a magnetic…

Mesoscale and Nanoscale Physics · Physics 2021-11-17 Robert Hussein , Wolfgang Belzig

We study the critical Josephson current flowing through a double quantum dot weakly coupled to two superconducting leads. We use analytical as well as numerical methods to investigate this setup in the limit of small and large bandwidth…

Mesoscale and Nanoscale Physics · Physics 2016-11-02 B. Probst , F. Domínguez , A. Schroer , A. Levy Yeyati , P. Recher

The infinite-U Anderson model is applied to transport through a quantum dot. The current and density of states are obtained via the non-crossing approximation for two spin-degenerate levels weakly coupled to two leads. At low temperatures,…

Condensed Matter · Physics 2009-10-22 Ned S. Wingreen , Yigal Meir

We study a multi-terminal Josephson junction based on an interacting quantum dot coupled to $n$ superconducting BCS leads. Using an Anderson type model of a local level with an arbitrary onsite Coulomb repulsion, we uncover its surprising…

Mesoscale and Nanoscale Physics · Physics 2024-04-23 Peter Zalom , Martin Žonda , T. Novotný

We present a theory of transport through interacting quantum dots coupled to normal and superconducting leads in the limit of weak tunnel coupling. A Josephson current between two superconducting leads, carried by first-order tunnel…

Superconductivity · Physics 2010-09-03 Marco G. Pala , Michele Governale , Jürgen König

We present a real-time diagrammatic theory for transport through interacting quantum dots tunnel coupled to normal and superconducting leads. Our formulation describes both the equilibrium and non-equilibrium superconducting proximity…

Superconductivity · Physics 2008-09-05 Michele Governale , Marco G. Pala , Jürgen König

The Josephson transport and the electronic properties of a quantum dot characterized by a single level coupled to superconducting leads is analyzed. Different approximations are used and compared: the mean field approximation, the second…

Condensed Matter · Physics 2009-11-07 E. Vecino , A. Martin-Rodero , A. Levy Yeyati

We study the transport properties of a serial double quantum dot (DQD) coupled to two superconducting leads, focusing on the Josephson current through the DQD and the associated 0-$\pi$ transitions which result from the subtle interplay…

Mesoscale and Nanoscale Physics · Physics 2011-03-31 Rok Zitko , Minchul Lee , Rosa Lopez , Ramon Aguado , Mahn-Soo Choi

Josephson junctions based on quantum dots offer a convenient tunability by means of local gates. Here we analyze a Josephson junction based on a serial double quantum dot in which the two dots are individually gated by phase-shifted…

Mesoscale and Nanoscale Physics · Physics 2023-04-12 Carlos Ortega-Taberner , Antti-Pekka Jauho , Jens Paaske