Modeling Energy Relaxation via Quantum Thermalization: A Superconducting Qubit Coupled to a Many-Body TLS System

Quantum Physics [Submitted on 4 Mar 2026] Modeling Energy Relaxation via Quantum Thermalization: A Superconducting Qubit Coupled to a Many-Body TLS System Xue-Yi Guo While two-level systems (TLS) in superconducting qubits are known to introduce phonon-mediated energy dissipation channels, many-body TLS systems themselves can also act as a distinct dissipation channel whose effect on qubit energy relaxation remains to be explored. In this work, we model and numerically simulate the irreversible thermalization-driven energy relaxation of a superconducting qubit coupled to a many-body TLS system. Our numerical results show that thermalization suppresses coherent energy exchange between the qubit and TLS, resulting in exponential energy decay. The relaxation times scale as T_1, T_2 \propto J^{-2}, where J denotes the qubit-TLS coupling strength. Moreover, T_1 is significantly affected by the internal coupling strength of the TLS system, the TLS frequency fluctuation rate, and the number of thermally excited TLS. This work provides a quantum thermalization perspective for understanding qubit energy relaxation and decoherence, with potential implications for decoherence scenarios in other open quantum systems. Subjects: Quantum Physics (quant-ph) Cite as: arXiv:2603.13322 [quant-ph]   (or arXiv:2603.13322v1 [quant-ph] for this version)   https://doi.org/10.48550/arXiv.2603.13322 Focus to learn more Submission history From: Xue-Yi Guo [view email] [v1] Wed, 4 Mar 2026 16:26:19 UTC (971 KB) Access Paper: HTML (experimental) view license Current browse context: quant-ph < prev   |   next > new | recent | 2026-03 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?)