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Related papers: Josephson-Junction Qubits with Controlled Coupling…

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We propose a scheme for tunable coupling of phase-coupled flux qubits. The phase-coupling scheme can provide a strong coupling strength of the order of Josephson coupling energy of Josephson junctions in the connecting loop, while the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Mun Dae Kim

We present theoretical schemes for performing high-fidelity one- and two-qubit pulsed gates for a superconducting flux qubit. The "IBM qubit" consists of three Josephson junctions, three loops, and a superconducting transmission line.…

Quantum Physics · Physics 2008-03-19 Frederico Brito , David P. DiVincenzo , Roger H. Koch , Matthias Steffen

We introduce a method for finding the required control parameters for a quantum computer that yields the desired quantum algorithm without invoking elementary gates. We concentrate on the Josephson charge-qubit model, but the scenario is…

Quantum Physics · Physics 2009-11-10 Antti O. Niskanen , Juha J. Vartiainen , Martti M. Salomaa

Josephson junctions form the essential non-linearity for almost all superconducting qubits. The junction is formed when two superconducting electrodes come within $\sim$1 nm of each other. Although the capacitance of these electrodes is a…

Superconducting circuits can exhibit quantized energy levels and long coherence times. Harnessing the anharmonicity offered by Josephson junctions, such circuits have been successfully employed as qubits, quantum limited amplifiers and…

Mesoscale and Nanoscale Physics · Physics 2025-06-24 Priya Sharma , Jens Koch , Eran Ginossar

We review experiments on small-capacitance Josephson junctions. When the Josephson junction is fabricated in the configuration of dc superconducting quantum interference device (SQUID), the Josephson coupling can be tuned IN SITU with an…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Michio Watanabe , David B. Haviland

Superconducting circuits comprising Josephson junctions have spurred significant research activity due to their promise to realize scalable quantum computers. Effective Hamiltonians for these systems have traditionally been derived assuming…

Quantum Physics · Physics 2025-10-02 Thomas J. Maldonado , Alejandro W. Rodriguez , Hakan E. Türeci

By coupling pairs of superconducting qubits through a small Josephson junction with a time-dependent flux bias, we show that arbitrary interactions involving any combination of Pauli matrices can be generated with a small number of drive…

Quantum Physics · Physics 2015-07-08 Eliot Kapit

Since the first demonstration of coherent control of a quantum state of a superconducting charge qubit a variety of Josephson-junction-based qubits have been implemented with remarkable progress in coherence time and read-out schemes.…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 T. Yamamoto , Yu. A. Pashkin , O. Astafiev , Y. Nakamura , J. S. Tsai

We demonstrate a planar, tunable superconducting qubit with energy relaxation times up to 44 microseconds. This is achieved by using a geometry designed to both minimize radiative loss and reduce coupling to materials-related defects. At…

Recent experiments have demonstrated superconducting transmon qubits with semiconductor nanowire Josephson junctions. These hybrid gatemon qubits utilize field effect tunability characteristic for semiconductors to allow complete qubit…

Mesoscale and Nanoscale Physics · Physics 2016-04-20 L. Casparis , T. W. Larsen , M. S. Olsen , F. Kuemmeth , P. Krogstrup , J. Nygård , K. D. Petersson , C. M. Marcus

We study an LC-circuit implemented using a current-biased Josephson junction (CBJJ) as a tunable coupler for superconducting qubits. By modulating the bias current, the junction can be tuned in and out of resonance and entangled with the…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Alexandre Blais , Alec Maassen van den Brink , A. M. Zagoskin

We propose an active mechanism for coupling the quantized mode of a nanomechanical resonator to the persistent current in the loop of a superconducting Josephson junction (or phase slip) flux qubit. This coupling is independently controlled…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Fei Xue , Y. D Wang , C. P. Sun , H. Okamoto , H. Yamaguchi , K. Semba

We present the design of a superconducting qubit that has circulating currents of opposite sign as its two states. The circuit consists of three nano-scale aluminum Josephson junctions connected in a superconducting loop and controlled by…

Condensed Matter · Physics 2009-10-31 T. P. Orlando , J. E. Mooji , Lin Tian , Caspar H. van der Wal , L. Levitov , Seth Lloyd , J. J. Mazo

We present a quantum computing scheme with atomic Josephson junction arrays. The system consists of a small number of atoms with three internal states and trapped in a far-off resonant optical lattice. Raman lasers provide the "Josephson"…

Quantum Physics · Physics 2011-07-26 Lin Tian , P. Zoller

Hybrid superconductor-semiconductor Josephson field-effect transistors (JoFETs) function as Josephson junctions with a gate-tunable critical current. Additionally, they can feature a non-sinusoidal current-phase relation (CPR) containing…

We replace the Josephson junction defining a three-junction flux qubit's properties with a tunable direct current superconducting quantum interference devices (DC-SQUID) in order to tune the qubit gap during the experiment. We observe…

Superconductivity · Physics 2015-05-19 Xiaobo Zhu , Alexander Kemp , Shiro Saito , Kouichi Semba

Hybrid semiconductor-superconductor qubits have recently emerged as a promising alternative to traditional platforms, combining material advantages with device-level tunability. A defining feature is their gate-tunable Josephson coupling,…

Any quantum computational network can be constructed with a sequence of the two-qubit diagonal quantum gates and one-qubit gates in two-state quantum systems. The universal construction of these quantum gates in the quantum systems and of…

Quantum Physics · Physics 2007-05-23 Xijia Miao

The development of large-scale superconducting quantum computing requires efficient in-situ control methods that allow high-fidelity operations at millikelvin temperatures. Superconducting circuits based on Josephson junctions offer a…