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The magnetic state of a quantum dot attached to superconducting leads is experimentally shown to be controlled by the superconducting phase difference across the dot. This is done by probing the relation between the Josephson current and…

Mesoscale and Nanoscale Physics · Physics 2015-06-11 R. Delagrange , D. J. Luitz , R. Weil , A. Kasumov , V. Meden , H. Bouchiat , R. Deblock

Carbon nanotube (CNT) Josephson junctions in the open quantum dot limit exhibit superconducting switching currents which can be controlled with a gate electrode. Shapiro voltage steps can be observed under radiofrequency current…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 J. -P. Cleuziou , W. Wernsdorfer , S. Andergassen , S. Florens , V. Bouchiat , Th. Ondarcuhu , M. Monthioux

We report on quantum dot based Josephson junctions designed specifically for measuring the supercurrent. From high-accuracy fitting of the current-voltage characteristics we determine the full magnitude of the supercurrent (critical…

Superconductivity · Physics 2007-09-19 H. Ingerslev Jørgensen , T. Novotný , K. Grove-Rasmussen , K. Flensberg , P. E. Lindelof

A model of a ladder of Josephson junctions in a magnetic field is considered. The topological features of the zero-temperature phase diagram, as a function of charging energy and small deviations from commensurability of the vortex lattice,…

Condensed Matter · Physics 2016-08-31 Enzo Granato

We compute the critical Josephson current through a single-molecule junction. As a model for a molecule with a bistable conformational degree of freedom, we study an interacting single-level quantum dot coupled to a two-level system and…

Superconductivity · Physics 2015-05-13 Andreas Schulz , Alex Zazunov , Reinhold Egger

We present theoretical results for the equilibrium Josephson current through an Anderson dot tuned into the magnetic regime, using Hirsch-Fye Monte Carlo simulations covering the complete crossover from Kondo-dominated physics to $\pi$…

Strongly Correlated Electrons · Physics 2009-11-10 F. Siano , R. Egger

The critical currents in Josephson junctions of conventional superconductors with macroscopic defects are calculated for different defect critical current densities as a function of the magnetic field. We also study the evolution of the…

Superconductivity · Physics 2009-10-31 N. Stefanakis , N. Flytzanis

We theoretically study the behavior of the critical current of a thermally-biased tunnel Josephson junction with a particular design, in which the electrodes of the junction are enclosed in two different superconducting loops pierced by…

Superconductivity · Physics 2022-07-20 Claudio Guarcello , Roberta Citro , Francesco Giazotto , Alessandro Braggio

In this proposal, we present an experimental setup based on superconducting circuits and Josephson junctions to explore the modification of Josephson coefficient in the presence of external magnetic field due to vacuum polarization of…

Superconductivity · Physics 2017-01-02 Ali Izadi Rad

The superconducting circuits involving Josephson junction offer macroscopic quantum two-level system (qubit) which are coupled to cavity resonators and are operated via microwave signals. In this work, we study the dynamics of…

Quantum Physics · Physics 2022-07-12 Prashant Shukla

We report systematic measurements of the critical current versus magnetic field patterns of annular Josephson junctions in a wide magnetic field range. A modulation of the envelope of the pattern, which depends on the junction width, is…

Superconductivity · Physics 2009-10-31 Andreas Franz , Andreas Wallraff , Alexey V. Ustinov

We report a theoretical study of the macroscopic quantum tunneling (MQT) in small Josephson junctions containing randomly distributed two-level systems. We focus on the magnetic field dependent crossover temperature $T_{cr}$ between the…

Superconductivity · Physics 2014-10-17 M. V. Fistul

In a quantum dot hybrid superconducting junction, the behavior of the supercurrent is dominated by Coulomb blockade physics, which determines the magnetic state of the dot. In particular, in a single level quantum dot singly occupied, the…

Mesoscale and Nanoscale Physics · Physics 2021-01-25 R. Delagrange , R. Weil , A. Kasumov , M. Ferrier , H. Bouchiat , R. Deblock

We study theoretically the critical current in semiconductor nanowire Josephson junction with strong spin-orbit interaction. The critical current oscillates by an external magnetic field. We reveal that the oscillation of critical current…

Mesoscale and Nanoscale Physics · Physics 2014-08-04 Tomohiro Yokoyama , Mikio Eto , Yuli V. Nazarov

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

A proximity-effect thermometer measures the temperature dependent critical supercurrent in a long superconductor - normal metal - superconductor (SNS) Josephson junction. Typically, the transition from the superconducting to the normal…

Superconductivity · Physics 2010-03-29 M. Meschke , J. T. Peltonen , H. Courtois , J. P. Pekola

We carry out an extensive experimental and theoretical study of the Josephson effect in S-N-S junctions made of a diffusive normal metal (N) embedded between two superconducting electrodes (S). Our experiments are performed on Nb-Cu-Nb…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 P. Dubos , H. Courtois , B. Pannetier , F. K. Wilhelm , A. D. Zaikin , G. Schon

We study the phenomenon of macroscopic quantum tunneling (MQT) in a finite size Josephson junction (JJ) with an externally applied magnetic field. As it is well known, the problem of MQT in a point-like JJ is reduced to the study of the…

Superconductivity · Physics 2008-07-18 Yu. N. Ovchinnikov , A. Barone , A. A. Varlamov

Numerical modeling of dependences ``critical current -- external magnetic field'' for geometrically symmetric $0-\pi$ Josephson junctions is performed. The calculation of critical current is reduced to non-linear eigenvalue problem. The…

Superconductivity · Physics 2007-05-23 J. A. Angelova , T. L. Boyadjiev

Low-capacitance Josephson junction systems as well as coupled quantum dots, in a parameter range where single charges can be controlled, provide physical realizations of quantum bits, discussed in connection with quantum computing. The…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Alexander Shnirman , Gerd Schoen
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