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Related papers: Josephson Amplifier for Qubit Readout

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We present experimental results on a dispersive scheme for reading out a Josephson phase qubit. A capacitively shunted dc-SQUID is used as a nonlinear resonator which is inductively coupled to the qubit. We detect the flux state of the…

Superconductivity · Physics 2015-05-20 T. Wirth , J. Lisenfeld , A. Lukashenko , A. V. Ustinov

Josephson parametric amplifier (JPA) engineering is a significant component in the quantum two-mode squeezed radar (QTMS), to enhance, for instance, radar performance and the detection range or bandwidth. In this study, we apply quantum…

In this note we describe Josephson parametric amplifier (JPA) matching networks based on Legendre polynomials. These networks typically exhibit lower ripple and gentler roll-off than Chebyshev networks with similar parameters, and can be…

Applied Physics · Physics 2023-03-06 Ryan Kaufman , Ofer Naaman

We present investigations of Josephson charge-phase qubits inductively coupled to a radio-frequency driven tank-circuit enabling the readout of the states by measuring the Josephson inductance of the qubit. The circuits including junctions…

We present a lumped-element Josephson parametric amplifier designed to operate with strong coupling to the environment. In this regime, we observe broadband frequency dependent amplification with multi-peaked gain profiles. We account for…

Fast discrimination between quantum states of superconducting artificial atoms is an important ingredient for quantum information processing. In circuit quantum electrodynamics, increasing the signal field amplitude in the readout…

We have controlled the measurement strength of the qubit readout process by using a Josephson bifurcation amplifier (JBA : an AC-driven SQUID). The optimum readout pulse changes the superposition state into an eigenstate. To clarify how a…

Superconductivity · Physics 2015-03-13 K. Kakuyanagi , H. Nakano , S. Kagei , R. Koibuchi , S. Saito , A. Lupascu , K. Semba

Broadband impedance-matched Josephson parametric amplifiers are key components for high-fidelity single-shot multi-qubit readout. Nowadays, several types of impedance matched parametric amplifiers have been proposed: the first is an…

Parametric amplification is essential for quantum measurement, enabling the amplification of weak microwave signals with minimal added noise. While Josephson-junction-based amplifiers have become standard in superconducting quantum…

Quantum Physics · Physics 2025-12-04 Danial Davoudi , Abdul Mohamed , Shabir Barzanjeh

The process of measurement of a phase qubit by a resonant microwave cavity is considered for various interactions between the qubit and the cavity. A novel quasiclassical approach is described based on adiabatic reversals of the qubit state…

Predicting the performance of traveling-wave parametric amplifiers (TWPAs) based on nonlinear elements like superconducting Josephson junctions (JJs) is vital for qubit read-out in quantum computers. The purpose of this article is twofold:…

Optimizing the performance of cryogenic quantum amplifiers is a key step toward achieving high-fidelity and scalable qubit readout. In this work, we present efficient and accurate modeling of a Josephson traveling-wave parametric amplifier…

Quantum Physics · Physics 2025-09-11 Likai Yang , Jennifer Wang , Mohamed Awida Hassan , Philip Krantz , Kevin P. O'Brien

We propose and demonstrate a frequency-multiplexed readout scheme in 3D cQED architecture. We use four transmon qubits coupled to individual rectangular cavities which are aperture-coupled to a common rectangular waveguide feedline. A…

Superconducting parametric amplifiers are crucial components in microwave quantum circuits for enabling quantum-limited signal readout. The best-performing such amplifiers are often based on Josephson junctions, which however are sensitive…

Quantum Physics · Physics 2022-11-17 Mingrui Xu , Risheng Cheng , Yufeng Wu , Gangqiang Liu , Hong X. Tang

In this paper we discuss solid-state nanoelectronic realizations of Josephson flux qubits with large tunneling amplitude between the two macroscopic states. The latter can be controlled via the height and wells form of the potential…

Superconductivity · Physics 2013-04-02 V. I. Shnyrkov , A. A. Soroka , S. I. Melnik

We propose a superconducting phase qubit on the basis of the radio-frequency SQUID with the screening parameter value $\beta_L = (2\pi/\Phi_0)LI_c \approx 1$, biased by a half flux quantum $\Phi_e=\Phi_0/2$. Significant anharmonicity ($>…

Superconductivity · Physics 2010-01-06 A. B. Zorin , F. Chiarello

We present a lumped-element Josephson parametric amplifier (JPA) utilizing a straightforward fabrication process involving a single electron beam lithography step followed by double-angle evaporation of aluminum and in-situ oxidation. The…

Mesoscale and Nanoscale Physics · Physics 2019-05-01 T. Elo , T. S. Abhilash , M. R. Perelshtein , I. Lilja , E. V. Korostylev , P. J. Hakonen

One of the central challenges in the development of parametric amplifiers is the control of the dynamic range relative to its gain and bandwidth, which typically limits quantum limited amplification to signals which contain only a few…

Superconductivity · Physics 2014-02-21 C. Eichler , A. Wallraff

We report on the design and characterization of a high-power amplifier with an output power of 36.5 dBm for a frequency range of 50 MHz to 1000 MHz with a total gain of 40 dB. The amplifier is optimized for driving acousto-optic and…

Eigen oscillations in a superconducting parallel plate resonator with the Josephson-coupled plates are investigated. While the insulator thickness S changes from tens of microns down to the decay lengthscale of the superconducting…

Superconductivity · Physics 2011-08-15 Vladimir V. Talanov