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Related papers: Cooper Pair Box Coupled to a Current-Biased Joseph…

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This paper illustrates a unified approach, classical circuit and control theories, to study a nonlinear LC circuit with a current dependent inductance as model of the Josephson junction, the mathematical analysis is complemented with…

Signal Processing · Electrical Eng. & Systems 2019-02-11 Alberto Delgado

We have realized controllable coupling between two three-junction flux qubits by inserting an additional coupler loop between them, containing three Josephson junctions. Two of these are shared with the qubit loops, providing strong…

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

In this letter, we investigate the dynamics of a single superconducting artificial atom capacitively coupled to a transmission line with a characteristic impedance comparable or larger than the quantum resistance. In this regime, microwaves…

Quantum Physics · Physics 2021-04-07 Emely Wiegand , Benjamin Rousseaux , Göran Johansson

We consider an array of Cooper Pair Boxes, each of which is coupled to a superconducting reservoir by a capacitive tunnel junction. We discuss two effects that probe not just the quantum nature of the islands, but also of the…

Superconductivity · Physics 2009-11-10 D. A. Rodrigues , B. L. Gyorffy , T. P. Spiller

We consider a two-level (TL) system with energy level separation Omega_0 inside a Josephson junction. The junction is shunted by a resistor R and is current I (or voltage V = RI) biased. If the TL system modulates the Josephson energy…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 I. Martin , L. Bulaevskii , A. Shnirman

Transportation of Cooper-pairs by a movable single Cooper-pair-box placed between two remote superconductors is shown to establish coherent coupling between them. This coupling is due to entanglement of the movable box with the leads and is…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 A. Isacsson , L. Y. Gorelik , R. I. Shekhter , Y. M. Galperin , M. Jonson

We analyze the impact of trap states in the oxide layer of a superconducting tunnel junctions, on the fluctuation of the Josephson critical current, thus on coherence in superconducting qubits. Two mechanisms are usually considered: the…

Mesoscale and Nanoscale Physics · Physics 2011-12-02 Mohammad H. Ansari , Frank K. Wilhelm

Josephson weak links in superconductors can be engineered such that the phase difference across the junction is $\pi$ ($\pi$-junction),leading to the reversal of the current. The conditions under which the analogous effect of supercurrent…

Condensed Matter · Physics 2007-05-23 E. Sakellari , N. P. Proukakis , M. Leadbeater , C. S. Adams

Rabi oscillations of quantum population are known to occur in two-level systems driven by spectrally narrow laser fields. In this work we study Rabi oscillations induced by shaped broadband femtosecond laser pulses. Due to the broad…

Quantum Physics · Physics 2015-05-30 S. Zhdanovich , J. W. Hepburn , V. Milner

We investigate the design and functionality of a network of loop-shaped charge qubits with switchable nearest-neighbor coupling. The qubit coupling is achieved by placing large Josephson junctions at the intersections of the qubit loops and…

Superconductivity · Physics 2016-08-31 M. Wallquist , J. Lantz , V. S. Shumeiko , G. Wendin

Environmental influences on the dynamics of a coupled qubit-oscillator system are studied analytically. We investigate the case of a quasi-degenerate qubit within the ultra-strong coupling regime for which the qubit frequency is much…

Quantum Physics · Physics 2014-01-28 Shantanu Agarwal , Sayed M. Hashemi Rafsanjani , Joseph H. Eberly

We present an analytical solution of the single photon quantum feedback in a cavity quantum electrodynamics system based on a half cavity set-up coupled to a structured continuum. The exact analytical expression we obtain allows us to…

We investigate the Josephson effect through a two-level quantum dot with an exchange coupling between two dot electrons. We compute the superconducting phase relationship and construct the phase diagram in the superconducting gap--exchange…

Mesoscale and Nanoscale Physics · Physics 2011-08-25 Minchul Lee , Thibaut Jonckheere , Thierry Martin

The Josephson supercurrent through the hybrid Majorana--quantum dot--Majorana junction is investigated. We particularly analyze the effect of spin-selective coupling between the Majorana and quantum dot states, which emerges only in the…

Mesoscale and Nanoscale Physics · Physics 2017-07-11 Luting Xu , Xin-Qi Li , Qing-Feng Sun

We present a stability analysis of an interacting two-species Bose-Einstein condensate driven by a quantized field in the semi-classical limit. Transitions from Rabi to Josephson dynamics are identified depending on both the inter-atomic…

Quantum Physics · Physics 2011-08-22 B. M. Rodríguez-Lara , Ray-Kuang Lee

We present Rabi oscillation measurements of a Nb/AlOx/Nb dc superconducting quantum interference device (SQUID) phase qubit with a 100 um^2 area junction acquired over a range of microwave drive power and frequency detuning. Given the…

Embedded in an ohmic environment, the Josephson current peak can transfer part of its weight to finite voltage and the junction becomes resistive. The dissipative environment can even suppress the superconducting effect of the junction via…

Mesoscale and Nanoscale Physics · Physics 2019-04-10 Tom Morel , Christophe Mora

The transmission of Cooper pairs between two weakly coupled superconductors produces a superfluid current and a phase difference; the celebrated Josephson effect. Because of time-reversal and parity symmetries, there is no Josephson current…

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