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Superconductivity and magnetism are competing effects that can coexist in certain regimes. Their co-existence leads to unexpected new behaviors that include the onset of exotic electron pair mechanisms and topological phases. In this work,…

We investigate the Josephson effect in TNT and NTN junctions, consisting of topological (T) and normal (N) phases of semiconductor-superconductor 1D heterostructures in the presence of a Zeeman field. A key feature of our setup is that, in…

Mesoscale and Nanoscale Physics · Physics 2013-06-10 Panagiotis Kotetes , Alexander Shnirman , Gerd Schön

We formulate a quantum waveguide theory of the Josephson effect in multiband superconductors, with special emphasis on iron-based materials. By generalizing the boundary conditions of the scattering problem, we first determine the Andreev…

Strongly Correlated Electrons · Physics 2015-12-09 Ciro Nappi , Francesco Romeo , Ettore Sarnelli , Roberta Citro

We have demonstrated strong antiferromagnetic coupling between two three-junction flux qubits based on a shared Josephson junction, and therefore not limited by the small inductances of the qubit loops. The coupling sign and magnitude were…

We study a superconducting quantum point contact made of a narrow In$_{0.75}% $Ga$_{0.25}$As channel with Nb proximity electrodes. The narrow channel is formed in a gate-fitted constriction of InGaAs/InAlAs/InP heterostructure hosting a…

Mesoscale and Nanoscale Physics · Physics 2014-04-23 Hiroshi Irie , Yuichi Harada , Hiroki Sugiyama , Tatsushi Akazaki

Fluxons in a superconducting loop can be coherently coupled by quantum phase slips occurring at a weak link such as a Josephson junction. If Cooper pair tunneling at the junction occurs through a resonant level, $2\pi$ quantum phase slips…

Mesoscale and Nanoscale Physics · Physics 2024-08-14 T. Vakhtel , P. D. Kurilovich , M. Pita-Vidal , A. Bargerbos , V. Fatemi , B. van Heck

We study a carbon nanotube quantum dot embedded into a SQUID loop in order to investigate the competition of strong electron correlations with proximity effect. Depending whether local pairing or local magnetism prevails, a superconducting…

Mesoscale and Nanoscale Physics · Physics 2012-02-16 Romain Maurand , Tobias Meng , Edgar Bonet , Serge Florens , Laëtitia Marty , Wolfgang Wernsdorfer

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

We propose a scheme to clarify the coupling nature between superconducting Josephson qubits andmicroscopic two-level systems. Although dominant interest in studying two-level systems was in phase qubits previously, we find that the…

Quantum Physics · Physics 2012-12-13 Zhen-Tao Zhang , Yang Yu

We show that a system of Josephson junctions coupled via low-resistance tunneling contacts to graphene substrate(s) may effectively operate as a current switching device. The effect is based on the dissipation-driven…

Superconductivity · Physics 2009-11-13 Roman M. Lutchyn , Victor Galitski , Gil Refael , S. Das Sarma

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 study the Josephson effect in a triplet superconductor--ferromagnet--singlet superconductor junction. We show that the interaction of tunneling Cooper pairs with the interface magnetization can permit a Josephson current at the lowest…

Superconductivity · Physics 2013-08-22 P. M. R. Brydon , Wei Chen , Yasuhiro Asano , Dirk Manske

In order to mimic the phase changes in the primordial Big Bang, several "cosmological" solid-state experiments have been conceived, during the last decade, to investigate the spontaneous symmetry breaking in superconductors and superfluids…

Superconductivity · Physics 2019-12-06 Roberto Monaco , Jesper Mygind , Valery K. Koshelets

By using analytical and Worldline Monte Carlo approaches, we investigate the effects induced by quantum phase fluctuations combined with quasiparticle subgap and shunt resistances on a small-capacitance Josephson junction. By using the…

A cylindrical Josephson junction with a spatially dependent Josephson coupling which averages to zero is studied in order to model the physics of a disk of d-wave superconductor embedded in a superconducting film of a different symmetry. It…

Condensed Matter · Physics 2009-10-22 A. J. Millis

We theoretically study the superconducting diode effect in a three-terminal Josephson junction. The diode effect in superconducting systems is typically related to the presence of a difference in the critical currents for currents flowing…

Superconductivity · Physics 2024-08-07 Jorge Huamani Correa , Michal P. Nowak

We propose to dynamically control the conductivity of a Josephson junction composed of two weakly coupled one dimensional condensates of ultracold atoms. A current is induced by a periodically modulated potential difference between the…

Quantum Gases · Physics 2021-02-10 Beilei Zhu , Vijay Pal Singh , Junichi Okamoto , Ludwig Mathey

We study the differential conductance in the Kondo regime of a quantum dot coupled to multiple leads. When the bias is applied symmetrically on two of the leads ($V$ and $-V$, as usual in experiments), while the others are grounded, the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 M. Tolea , I. V. Dinu , A. Aldea

We study the Josephson coupling between two superconductors through a single correlated molecular level, including Coulomb interaction on the level and coupling to a bosonic environment. All calculations are done to the lowest, i.e., the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Tomas Novotny , Alessandra Rossini , Karsten Flensberg

Planar Josephson junctions in a magnetic field exhibit the superconducting diode effect, by which the critical current magnitude depends on the polarity of the transport current. A number of different mechanisms for the effect have been…

Mesoscale and Nanoscale Physics · Physics 2025-12-11 William F. Schiela , Melissa Mikalsen , William M. Strickland , Javad Shabani