Time-optimal Qubit Reset via Environmental Spectral Structure

Quantum Physics [Submitted on 23 Apr 2026] Time-optimal Qubit Reset via Environmental Spectral Structure Hong-Bo Huang, Hui Dong Fast qubit reset is essential for qubit reuse in the noisy intermediate-scale quantum computing era, yet it conflicts with the weak decoherence required for high-fidelity computation. We solve the time-optimal reset problem for a frequency-tunable qubit coupled to a structural environment under realistic spectral and control constraints. The optimal strategy consists of a switch--restore--switch sequence, where the qubit is moved from a low-decoherence computational configuration to a high-decoherence restoring configuration and then returned for reuse. For superconducting qubits in four representative environments, this strategy reduces the reset time from typically \gtrsim\SI{100}{\nano\second}$\gtrsim\SI{100}{\nano\second}$ to \SI{20}{\nano\second}$\SI{20}{\nano\second}$, about 40\% of a typical two-qubit gate time, while achieving a reset precision of 10^{-5}. Our results identify environmental spectral structure as a practical resource for rapid, high-fidelity qubit reset and provide a design principle for qubit reuse on qubit-limited processors. Comments: 7 pages, 4 figures Subjects: Quantum Physics (quant-ph) Cite as: arXiv:2604.21230 [quant-ph]   (or arXiv:2604.21230v1 [quant-ph] for this version)   https://doi.org/10.48550/arXiv.2604.21230 Focus to learn more Submission history From: HongBo Huang [view email] [v1] Thu, 23 Apr 2026 02:54:12 UTC (222 KB) Access Paper: HTML (experimental) view license Current browse context: quant-ph < prev   |   next > new | recent | 2026-04 References & Citations INSPIRE HEP NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)