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Related papers: Controllable Coupling in Phase-Coupled Flux Qubits

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We propose a scheme to implement variable coupling between two flux qubits using the screening current response of a dc Superconducting QUantum Interference Device (SQUID). The coupling strength is adjusted by the current bias applied to…

Applications for noisy intermediate-scale quantum computing devices rely on the efficient entanglement of many qubits to reach a potential quantum advantage. Although entanglement is typically generated using two-qubit gates, direct control…

Quantum Physics · Physics 2023-04-18 Niklas J. Glaser , Federico Roy , Stefan Filipp

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 show that two capacitively-coupled Josephson junctions, in the quantum limit, form a simple coupled qubit system with effective coupling controlled by the junction bias currents. We compute numerically the energy levels and wave…

In this work we show that a tunable coupling between microwave resonators can be engineered by means of simple Josephson junctions circuits, such as dc- and rf-SQUIDs. We show that by controlling the time dependence of the coupling it is…

Superconductivity · Physics 2013-04-10 B. Peropadre , D. Zueco , F. Wulschner , F. Deppe , A. Marx , R. Gross , J. J. García-Ripoll

Recent progress in superconducting qubits has demonstrated the potential of these devices for the future of quantum information processing. One desirable feature for quantum computing is independent control of qubit interactions as well as…

Superconductivity · Physics 2011-06-14 S. J. Srinivasan , A. J. Hoffman , J. M. Gambetta , A. A. Houck

This paper presents a theoretical analysis of the recently realized tuneable coupler for superconducting phase qubits (R. C. Bialczak et al., Ref.\ \protect\onlinecite{Bialczak}). The coupling can be turned off by compensating a negative…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 Ricardo A. Pinto , Alexander N. Korotkov , Michael R. Geller , Vitaly S. Shumeiko , John M. Martinis

Parametric modulation, valued for its versatility, is widely employed in superconducting circuits for quantum simulations and high-fidelity two-qubit gates. Conventionally, the qubit coupling strength is determined by the amplitude of the…

Quantum Physics · Physics 2025-11-25 Zhuang Ma , Xianke Li , Hongyi Shi , Ruonan Guo , Jianwen Xu , Xinsheng Tan , Yang Yu

It is sketched how a monostable rf- or dc-SQUID can mediate an inductive coupling between two adjacent flux qubits. The nontrivial dependence of the SQUID's susceptibility on external flux makes it possible to continuously tune the induced…

Superconductivity · Physics 2007-05-23 Alec Maassen van den Brink , A. J. Berkley , M. Yalowsky

Low-capacitance Josephson junctions, where Cooper pairs tunnel coherently while Coulomb blockade effects allow the control of the total charge, provide physical realizations of quantum bits (qubits), with logical states differing by one…

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

We have designed and experimentally implemented a circuit of inductively-coupled superconducting charge qubits, where a Josephson junction is used as an inductance, and the coupling between the qubits is controlled by an applied magnetic…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 T. Yamamoto , M. Watanabe , J. Q. You , Yu. A. Pashkin , O. Astafiev , Y. Nakamura , F. Nori , J. S. Tsai

The ability to non-dissipatively tune the Josephson coupling energy of Josephson junctions is a useful tool in frequency-tunable qubits. This is typically done by threading magnetic flux through two junctions connected in a loop, a geometry…

Mesoscale and Nanoscale Physics · Physics 2026-02-26 Maxwell Wisne , Venkat Chandrasekhar

We theoretically investigate selective coupling of superconducting charge qubits mediated by a superconducting stripline cavity with a tunable resonance frequency. The frequency control is provided by a flux biased dc-SQUID attached to the…

Superconductivity · Physics 2009-11-11 M. Wallquist , V. S. Shumeiko , G. Wendin

The superconducting fluxonium circuit is an RF-SQUID-type flux qubit that uses a large inductance built from an array of Josephson junctions or a high kinetic inductance material. This inductance suppresses charge sensitivity exponentially…

Quantum Physics · Physics 2022-04-01 I. N. Moskalenko , I. S. Besedin , I. A. Simakov , A. V. Ustinov

Superconducting quantum circuits typically use capacitive charge-based linear coupling schemes to control interactions between elements such as qubits. While simple and effective, this coupling scheme makes it difficult to satisfy competing…

Quantum Physics · Physics 2026-02-04 Gihwan Kim , Andreas Butler , Oskar Painter

Tunable Josephson harmonics open new avenues for qubit design. We demonstrate a superconducting circuit element consisting of a tunnel junction in series with a SQUID loop, yielding a Josephson potential whose harmonic content is strongly…

Exploiting the intrinsic nonlinearity of superconducting Josephson junctions, we propose a scalable circuit with superconducting qubits (SCQs) which is very similar to the successful one now being used for trapped ions. The SCQs are coupled…

Superconductivity · Physics 2015-06-25 Yu-xi Liu , L. F. Wei , J. R. Johansson , J. S. Tsai , Franco Nori

We have investigated the flux transfer characteristics of a switchable flux transformer comprising a superconducting loop and a DC superconducting quantum interference device (DC-SQUID). This system can be used to couple multiple flux…

Superconductivity · Physics 2007-05-23 Y. Shimazu , T. Niizeki

We have analyzed and proposed coupling mechanisms between Three Josephson Junction Flux Qubits (3JJQ). For this, we have developed a numerical method to extract the effective Hamiltonian of a system of coupled qubits via the…

Quantum Physics · Physics 2021-10-26 Gabriel Jaumà

Superconducting tunnel junctions constitute the units of superconducting quantum circuits and are massively used both for quantum sensing and quantum computation. In previous works, we predicted the existence of a nonlinear thermoelectric…

Mesoscale and Nanoscale Physics · Physics 2020-10-21 G. Marchegiani , A. Braggio , F. Giazotto