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Related papers: Raising the Cavity Frequency in cQED

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Error rates in current noisy quantum hardware are not static; they vary over time and across qubits. This temporal and spatial variation challenges the effectiveness of fixed-distance quantum error correction (QEC) codes. In this paper, we…

Quantum Physics · Physics 2025-05-12 Subrata Das , Swaroop Ghosh

We present a superconducting device that realizes the sequential measurement of a transmon qubit. The device disables common limitations of dispersive readout such as Purcell effect or transients in the cavity mode by turning on and off the…

Quantum Physics · Physics 2020-05-08 Théau Peronnin , Danijela Marković , Quentin Ficheux , Benjamin Huard

Cavity quantum electrodynamic (QED) is studied for two strongly-coupled charge qubits interacting with a single-mode quantized field, which is provided by a on-chip transmission line resonator. We analyze the dressed state structure of this…

Quantum Physics · Physics 2007-05-23 Y. D. Wang , H. T. Quan , Yu-xi Liu , C. P. Sun , Franco Nori

Fault-tolerant spin-based quantum computers will require fast and accurate qubit readout. This can be achieved using radio-frequency reflectometry given sufficient sensitivity to the change in quantum capacitance associated with the qubit…

The fidelity of certain gates on noisy quantum computers may be improved when they are implemented using more than two levels of the involved transmons. The main impediments to achieving this potential are the dynamic gate phase errors that…

Quantum Physics · Physics 2024-07-30 Yutaro Iiyama , Wonho Jang , Naoki Kanazawa , Ryu Sawada , Tamiya Onodera , Koji Terashi

The strong coupling limit of cavity quantum electrodynamics (QED) implies the capability of a matter-like quantum system to coherently transform an individual excitation into a single photon within a resonant structure. This not only…

The unique features of quantum theory offer a powerful new paradigm for information processing. Translating these mathematical abstractions into useful algorithms and applications requires quantum systems with significant complexity and…

Quantum Physics · Physics 2021-04-13 Atharv Joshi , Kyungjoo Noh , Yvonne Y. Gao

The realization of fault-tolerant quantum computing requires the execution of quantum error-correction (QEC) schemes, to mitigate the fragile nature of qubits. In this context, to ensure the success of QEC, a protocol capable of…

Exploring an efficient and scalable architecture of fault-tolerant quantum computing (FTQC) is vital for demonstrating useful quantum computing. Here, we propose and evaluate a scalable and practical architecture with a…

Quantum Physics · Physics 2025-04-29 Rui Asaoka , Yasunari Suzuki , Yuuki Tokunaga

Designing quantum systems with the measurement speed and accuracy needed for quantum error correction using superconducting qubits requires iterative design and test informed by accurate models and characterization tools. We introduce a…

Quantum computing roadmaps predict the availability of 10,000 qubit devices within the next 3-5 years. With projected two-qubit error rates of 0.1%, these systems will enable certain operations under quantum error correction (QEC) using…

Stark shift on a superconducting qubit in circuit quantum electrodynamics (QED) has been used to construct universal quantum entangling gates on superconducting resonators in previous works. It is a second-order coupling effect between the…

Quantum Physics · Physics 2015-03-12 Ming Hua , Ming-Jie Tao , Fu-Guo Deng

We study bifurcation measurement of a multi-level superconducting qubit using a nonlinear resonator biased in the straddling regime, where the resonator frequency sits between two qubit transition frequencies. We find that high-fidelity…

Quantum Physics · Physics 2012-09-27 Maxime Boissonneault , J. M. Gambetta , A. Blais

The speed of quantum gates and measurements is a decisive factor for the overall fidelity of quantum protocols when performed on physical qubits with finite coherence time. Reducing the time required to distinguish qubit states with high…

Superconducting qubits are one of the most promising candidates to implement quantum computers. The superiority of superconducting quantum computers over any classical device in simulating random but well-determined quantum circuits has…

Cavity quantum electrodynamics (cQED) provides strong light-matter interactions that can be used for manipulating and detecting quantum states. The interaction can be enhanced by increasing the resonator's impedance, while approaching the…

Mesoscale and Nanoscale Physics · Physics 2026-02-12 Chaojing Lin , Kosei Teshima , Takafumi Akiho , Koji Muraki , Toshimasa Fujisawa

We revisit the superstrong coupling regime of multi-mode cavity quantum electrodynamics (QED), defined to occur when the frequency of vacuum Rabi oscillations between the qubit and the nearest cavity mode exceeds the cavity's free spectral…

Quantum Physics · Physics 2022-10-27 Nitish Mehta , Cristiano Ciuti , Roman Kuzmin , Vladimir E. Manucharyan

Finding strategies to preserve quantum resources in open systems is nowadays a main requirement for reliable quantum-enhanced technologies. We address this issue by considering structured cavities embedding qubits driven by a control…

Quantum Physics · Physics 2018-09-18 Ali Mortezapour , Rosario Lo Franco

By modeling the coupling of multiple superconducting qubits to a single cavity in the circuit-quantum electrodynamics (QED) framework we find that it should be possible to observe superradiance and phase multistability using currently…

Quantum Physics · Physics 2015-05-19 Michael Delanty , Stojan Rebic , Jason Twamley

The future development of quantum information using superconducting circuits requires Josephson qubits [1] with long coherence times combined to a high-fidelity readout. Major progress in the control of coherence has recently been achieved…