1. Benchmarking Single-Qubit Gates on a Noise-Biased Qubit Beyond the Fault-Tolerant Threshold
- Author
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Qing, Bingcheng, Hajr, Ahmed, Wang, Ke, Koolstra, Gerwin, Nguyen, Long B., Hines, Jordan, Huang, Irwin, Bhandari, Bibek, Padramrazi, Zahra, Chen, Larry, Kang, Ziqi, Jünger, Christian, Goss, Noah, Jain, Nikitha, Kim, Hyunseong, Lee, Kan-Heng, Hashim, Akel, Frattini, Nicholas E., Dressel, Justin, Jordan, Andrew N., Santiago, David I., and Siddiqi, Irfan
- Subjects
Quantum Physics - Abstract
The ubiquitous noise in quantum system hinders the advancement of quantum information processing and has driven the emergence of different hardware-efficient quantum error correction protocols. Among them, qubits with structured noise, especially with biased noise, are one of the most promising platform to achieve fault-tolerance due to the high error thresholds of quantum error correction codes tailored for them. Nevertheless, their quantum operations are challenging and the demonstration of their performance beyond the fault-tolerant threshold remain incomplete. Here, we leverage Schr\"odinger cat states in a scalable planar superconducting nonlinear oscillator to thoroughly characterize the high-fidelity single-qubit quantum operations with systematic quantum tomography and benchmarking tools, demonstrating the state-of-the-art performance of operations crossing the fault-tolerant threshold of the XZZX surface code. These results thus embody a transformative milestone in the exploration of quantum systems with structured error channels. Notably, our framework is extensible to other types of structured-noise systems, paving the way for systematic characterization and validation of novel quantum platforms with structured noise., Comment: 19 pages, 12 figures
- Published
- 2024