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Related papers: High-fidelity gates in a Josephson qubit

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High-fidelity quantum gates are crucial for achieving fault-tolerant quantum computing; however, decoherence significantly reduces gate fidelities during long operation times. Although optimal control techniques can theoretically minimize…

Quantum Physics · Physics 2026-02-27 Niril George , Joseph L. Allen , Robert Kosut , Eran Ginossar

Parasitic two-level-system (TLS) defects limit the stability and performance of solid-state quantum processors. Their interaction with a qubit can cause discrete, stochastic shifts of the qubit frequency, making the qubit bistable. We…

Several logical qubits and quantum gates have been proposed for semiconductor quantum dots controlled by voltages applied to top gates. The different schemes can be difficult to compare meaningfully. Here we develop a theoretical framework…

Mesoscale and Nanoscale Physics · Physics 2013-12-09 Teck Seng Koh , S. N. Coppersmith , Mark Friesen

Fault-tolerant quantum computing demands many qubits with long lifetimes to conduct accurate quantum gate operations. However, external noise limits the computing time of physical qubits. Quantum error correction codes may extend such…

Quantum Physics · Physics 2018-10-03 Chungheon Baek , Tomohiro Ostuka , Seigo Tarucha , Byung-Soo Choi

Semiconductor spin qubits demonstrated single-qubit gates with fidelities up to $99.9\%$ benchmarked in the single-qubit subspace. However, tomographic characterizations reveals non-negligible crosstalk errors in a larger space.…

Silicon spin qubits are a promising platform for scalable quantum computing due to their compatibility with industrial semiconductor fabrication and the recent scaling to multi-qubit devices. Control fidelities above the 99% fault-tolerant…

We study the speed/fidelity trade-off for a two-qubit phase gate implemented in $^{43}$Ca$^+$ hyperfine trapped-ion qubits. We characterize various error sources contributing to the measured fidelity, allowing us to account for errors due…

Quantum Physics · Physics 2016-08-10 C. J. Ballance , T. P. Harty , N. M. Linke , D. M. Lucas

High-fidelity, efficient quantum nondemolition readout of quantum bits is integral to the goal of quantum computation. As superconducting circuits approach the requirements of scalable, universal fault tolerance, qubit readout must also…

Fault-tolerant quantum computation requires low physical-qubit gate errors. Many approaches exist to reduce gate errors, including both hardware- and control-optimization strategies. Dynamically corrected gates are designed to cancel…

Quantum Physics · Physics 2024-12-13 Habitamu Y. Walelign , Xinxin Cai , Bikun Li , Edwin Barnes , John M. Nichol

Quantum gates in experiment are inherently prone to errors that need to be characterized before they can be corrected. Full characterization via quantum process tomography is impractical and often unnecessary. For most practical purposes,…

Using error correcting codes and fault tolerant techniques, it is possible, at least in theory, to produce logical qubits with significantly lower error rates than the underlying physical qubits. Suppose, however, that the gates that act on…

Quantum Physics · Physics 2016-12-06 M. B. Hastings

Quantum computers require high fidelity quantum gates. These gates are obtained by routine calibration tasks that eat into the availability of cloud-based devices. Restless circuit execution speeds-up characterization and calibration by…

Quantum Physics · Physics 2023-11-10 Conrad J. Haupt , Daniel J. Egger

Current noisy quantum computers have multiple types of errors, which can occur in the state preparation, measurement/readout, and gate operation, as well as intrinsic decoherence and relaxation. Partly motivated by the booming of…

Quantum Physics · Physics 2025-05-07 Hongye Yu , Tzu-Chieh Wei

Fault tolerant protocol assumes the application of error correction after every quantum gate. However, correcting errors is costly in terms of time and number of qubits. Here we demonstrate that quantum error correction can be applied…

Quantum Physics · Physics 2015-06-18 Yaakov S. Weinstein

We propose and experimentally demonstrate a global parametric gate that generates multi-qubit entangled states in a single step. By applying a parametric drive to a common qubit at precise detunings relative to computational qubits, we…

The development of robust architectures capable of large-scale fault-tolerant quantum computation should consider both their quantum error-correcting codes, and the underlying physical qubits upon which they are built, in tandem. Following…

Quantum Physics · Physics 2021-10-19 Andrew S. Darmawan , Benjamin J. Brown , Arne L. Grimsmo , David K. Tuckett , Shruti Puri

In this paper, we examine various software and hardware strategies for implementing high-fidelity controlled-Z gate in the large-scale quantum system by solving the system's Hamiltonian with the Lindblad master equation. First, we show that…

Quantum Physics · Physics 2022-12-09 Dowon Baek , Seong Hyeon Park , Suhwan Choi , Chanwoo Yoo , Seungyong Hahn

Silicon offers an attractive material platform for hardware realization of quantum computing. In this study, a microscopic stochastic simulation method is developed to model the effect of random interface charge traps in silicon…

Quantum Physics · Physics 2020-11-12 Tong Wu , Jing Guo

In a Josephson phase qubit the coherent manipulations of the computational states are achieved by modulating an applied ac current, typically in the microwave range. In this work we show that it is possible to find optimal modulations of…

Mesoscale and Nanoscale Physics · Physics 2010-09-08 Shabnam Safaei , Simone Montangero , Fabio Taddei , Rosario Fazio

Because of their long coherence time and compatibility with industrial foundry processes, electron spin qubits are a promising platform for scalable quantum processors. A full-fledged quantum computer will need quantum error correction,…