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We have performed the first experiments in a superconductor - normal metal - superconductor single electron transistor in which there is an extra superconducting strip partially overlapping the normal metal island in good metal-to-metal…

Superconductivity · Physics 2009-10-31 A. J. Manninen , R. S. Poikolainen , T. V. Ryynanen , J. P. Pekola

Josephson current of spin-entangled electrons through the two branches of a SQUID-like structure with two quantum dots exhibits a magnetic-flux response different from the conventional Josephson current. Due to their interference, the…

Superconductivity · Physics 2011-11-15 Zhi Wang , Xiao Hu

The superconductor-to-insulator quantum phase transition in resistively shunted Josephson junctions is investigated by means of path-integral Monte Carlo simulations. This numerical technique allows us to directly access the (previously…

Superconductivity · Physics 2009-11-07 Carlos P. Herrero , Andrei D. Zaikin

The dc Josephson current through a long SNS junction receives contributions from both Andreev bound states localized in the normal region as well as from scattering states incoming from the superconducting leads. We show that in the limit…

Superconductivity · Physics 2013-02-20 Domenico Giuliano , Ian Affleck

We study a quantum computing system using microwave photons in transmission line resonators on a superconducting chip as qubits. We show that all control necessary for quantum computing can be implemented by coupling to Josephson devices on…

Quantum Physics · Physics 2015-05-14 Lianghui Du , Yong Hu , Zheng-Wei Zhou , Guang-Can Guo , Xingxiang Zhou

Quantum dots attached to BCS superconducting leads exhibit a $0-\pi$ impurity quantum phase transition, which can be experimentally controlled either by the gate voltage or by the superconducting phase difference. For the pertinent…

Mesoscale and Nanoscale Physics · Physics 2020-07-27 Alžběta Kadlecová , Martin Žonda , Vladislav Pokorný , Tomáš Novotný

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 discuss heat transport through a Josephson tunnel junction under various bias conditions. We first derive the formula for the cooling power of the junction valid for arbitrary time dependence of the Josephson phase. Combining it with the…

Mesoscale and Nanoscale Physics · Physics 2013-04-04 Dmitry Golubev , Timothé Faivre , Jukka P. Pekola

We examine in theory and by numerical simulation, the dynamic process of switching from a zero voltage to a finite voltage state in a Josephson junction circuit. The theoretical model describes small capacitance Josephson junctions which…

Superconductivity · Physics 2009-11-11 J. Sjostrand , J. Walter , E. Tholen , H. Hansson , D. Haviland , A. Karlhede

Superconducting qubits are solid state electrical circuits fabricated using techniques borrowed from conventional integrated circuits. They are based on the Josephson tunnel junction, the only non-dissipative, strongly non-linear circuit…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 M. H. Devoret , A. Wallraff , J. M. Martinis

We investigate superconducting quantum interference devices consisting of two highly transmissive Josephson junctions coupled by a superconducting loop, all defined in an epitaxial InAs/Al heterostructure. A novel device design allows for…

Mesoscale and Nanoscale Physics · Physics 2020-06-16 F. Nichele , E. Portolés , A. Fornieri , A. M. Whiticar , A. C. C. Drachmann , T. Wang , G. C. Gardner , C. Thomas , A. T. Hatke , M. J. Manfra , C. M. Marcus

We report the observation of quantum jumps between macroscopic quantum states in a superconducting phase qubit coupled to the two-level systems in the Josephson tunnel junction, and all key features of quantum jumps are confirmed in the…

Quantum Physics · Physics 2009-11-13 Yang Yu , Shi-Liang Zhu , Guozhu Sun , Xueda Wen , Ning Dong , Jian Chen , Peiheng Wu , Siyuan Han

We show that injecting nonequilibrium spins into the superconducting leads strongly enhances the stationary Josephson current through a superconductor-ferromagnet-superconductor junction. The resulting long-range super-current through a…

Superconductivity · Physics 2015-06-11 A. G. Mal'shukov , Arne Brataas

An interaction-free measurement protocol is described for a quantum circuit consisting of a superconducting qubit and a read-out Josephson junction. By measuring the state of the qubit one can ascertain the presence of a current pulse…

Superconductivity · Physics 2009-11-13 G. S. Paraoanu

Josephson junctions enable dissipation-less electrical current through metals and insulators below a critical current. Despite being central to quantum technology based on superconducting quantum bits and fundamental research into…

Interest in Josephson junctions (JJs) has increased rapidly in recent years not only because of their use in qubits and other quantum devices but also due to the unique physics supported by the JJs. The advent of various novel quantum…

Josephson junctions translate quantum phase coherence into an electrical response and underpin superconducting sensors and quantum circuits. In conventional junctions, the barrier acts primarily as a passive weak link, however, when the…

The stationary Josephson current in a ballistic graphene system is theoretically studied with focus on a planar junction consisting of a monolayer graphene sheet on top of which a pair of superconducting electrodes is deposited. To…

Mesoscale and Nanoscale Physics · Physics 2020-08-26 Yositake Takane

The Hamiltonian of a charge qubit, which consists of two Josephson junctions is found within well known quantum mechanical procedure. The inductance of the qubit is included from the very beginning. It allows a selfconsistent derivation of…

Superconductivity · Physics 2007-05-23 Ya. S. Greenberg , W. Krech

Due to their unique properties as lossless, nonlinear circuit elements, Josephson junctions lie at the heart of superconducting quantum information processing. Previously, we demonstrated a two-layer, submicrometer-scale overlap junction…