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Related papers: Multi-qubit time-varying quantum channels for NISQ…

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Recent experimental studies have shown that the relaxation time, $T_1$, and the dephasing time, $T_2$, of superconducting qubits fluctuate considerably over time. Time-varying quantum channel (TVQC) models have been proposed in order to…

Quantum Physics · Physics 2022-02-01 Josu Etxezarreta Martinez , Patricio Fuentes , Pedro Crespo , Javier Garcia-Frias

We benchmark the decoherence of superconducting qubits to examine the temporal stability of energy-relaxation and dephasing. By collecting statistics during measurements spanning multiple days, we find the mean parameters $\overline{T_{1}}$…

The fidelity of operations on a solid-state quantum processor is fundamentally bounded by environmental decoherence. Characterizing environmental fluctuations is challenging because the acquisition time of nonadaptive experimental protocols…

Superconducting qubits are an attractive platform for quantum computing since they have demonstrated high-fidelity quantum gates and extensibility to modest system sizes. Nonetheless, an outstanding challenge is stabilizing their…

Temporal fluctuations in the superconducting qubit lifetime, $T_1$, bring up additional challenges in building a fault-tolerant quantum computer. While the exact mechanisms remain unclear, $T_1$ fluctuations are generally attributed to the…

Superconducting qubits are a leading candidate for quantum computing but display temporal fluctuations in their energy relaxation times T1. This introduces instabilities in multi-qubit device performance. Furthermore, autocorrelation in…

Quantum Physics · Physics 2022-06-29 Malcolm Carroll , Sami Rosenblatt , Petar Jurcevic , Isaac Lauer , Abhinav Kandala

We discuss decoherence due to electromagnetic fluctuations in charge qubits formed by two lateral quantum dots. We use an effective circuit model to evaluate correlations of voltage fluctuations in the qubit setup. These correlations allows…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 Diego C. B. Valente , Eduardo R. Mucciolo , F. K. Wilhelm

We have investigated temporal fluctuation of superconducting qubits via the time-resolved measurement for an IBM Quantum system. We found that the qubit error rate abruptly changes during specific time intervals. Each high error state…

Quantum Physics · Physics 2025-08-22 Yuta Hirasaki , Shunsuke Daimon , Naoki Kanazawa , Toshinari Itoko , Masao Tokunari , Eiji Saitoh

Scalable quantum information processing requires the ability to tune multi-qubit interactions. This makes the precise manipulation of quantum states particularly difficult for multi-qubit interactions because tunability unavoidably…

State-of-the-art superconducting quantum processors containing tens to hundreds of qubits have demonstrated the building blocks for realizing fault-tolerant quantum computation. Nonetheless, a fundamental barrier to scaling further is the…

We have investigated instability of a superconducting quantum computer by continuously monitoring the qubit output. We found that qubits exhibit a step-like change in the error rates. This change is repeatedly observed, and each step…

Quantum Physics · Physics 2024-03-15 Yuta Hirasaki , Shunsuke Daimon , Toshinari Itoko , Naoki Kanazawa , Eiji Saitoh

Characterising the time over which quantum coherence survives is critical for any implementation of quantum bits, memories and sensors. The usual method for determining a quantum system's decoherence rate involves a suite of experiments…

We present a multifractal analysis of time series data obtained by repeatedly running a single-qubit quantum circuit on IBM superconducting quantum computers, in which the measurement outcomes are recorded as the number of zeros. By…

Quantum Physics · Physics 2025-12-23 Mohammadreza Saghafi , Lamine Mili , Karlton Wirsing

Temporal, spectral, and sample-to-sample fluctuations in coherence properties of qubits form an outstanding challenge for the development of upscaled fault-tolerant quantum computers. A ubiquitous source for these fluctuations in…

Quantum Physics · Physics 2021-10-29 Shlomi Matityahu , Alexander Shnirman , Moshe Schechter

We report on long-term measurements of a highly coherent, non-tunable superconducting transmon qubit, revealing low-frequency burst noise in coherence times and qubit transition frequency. We achieve this through a simultaneous measurement…

Over the past decade, research in quantum computing has tended to fall into one of two camps: near-term intermediate scale quantum (NISQ) and fault-tolerant quantum computing (FTQC). Yet, a growing body of work has been investigating how to…

Quantum Physics · Physics 2024-09-02 Amara Katabarwa , Katerina Gratsea , Athena Caesura , Peter D. Johnson

With the long coherence time, the fixed-frequency transmon qubit is a promising qubit modality for quantum computing. Currently, diverse qubit architectures that utilize fixed-frequency transmon qubits have been demonstrated with…

Quantum Physics · Physics 2022-06-29 Peng Zhao , Teng Ma , Yirong Jin , Haifeng Yu

Progress in fabrication of semiconductor and superconductor qubits has greatly diminished the number of decohering defects, thus decreasing the devastating low-frequency $1/f$ noise and extending the qubits' coherence times (dephasing time…

Mesoscale and Nanoscale Physics · Physics 2024-08-23 M. Mehmandoost , V. V. Dobrovitski

Since the very first experiments, superconducting circuits have suffered from strong coupling to environmental noise, destroying quantum coherence and degrading performance. In state-of-the-art experiments, it is found that the relaxation…

Mesoscale and Nanoscale Physics · Physics 2015-08-04 Clemens Müller , Jürgen Lisenfeld , Alexander Shnirman , Stefano Poletto

Superconducting qubits have been used in the most advanced demonstrations of quantum information processing, and they can be manufactured at-scale using proven semiconductor techniques. This makes them one of the leading technologies in the…

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