Observation of quantum multi-Mpemba effect in a trapped-ion system

Quantum Physics [Submitted on 23 Apr 2026] Observation of quantum multi-Mpemba effect in a trapped-ion system Gang Xia, Yu-Jie Zheng, Jing Huang, Chun-Wang Wu, Yi Xie, Ting Chen, Wei Wu, Weibin Li, Hui Jing, Jie Zhang, Yan-Li Zhou, Ping-Xing Chen The quantum Mpemba effect (ME) in Markovian systems is conventionally explained by a smaller overlap between the initial state and the slowest decay mode (SDM). Such state, initially farther away from equilibrium or steady state, relaxes faster than closer ones, resulting to a crossing of their trajectories. This picture, by neglecting the transient dynamics, holds in the long-time limit. Here we experimentally observe multiple trajectory crossings (multi-ME) in the relaxation dynamics of a trapped ion. Such novel dynamics takes place in a unusual scenario where the initial state instead has a larger overlap with the SDM. We develop a theoretical framework based on relaxation speed to understand the multi-ME. We show that the initial relaxation speed is governed by the fastest decay mode, which together with the SDM overlap gives a phase diagram that reveals both the occurrence and the types of quantum ME observed in our experiment. Our study goes beyond the simple picture based on the long-time limit, tracks continuously the quantum ME dynamics, and establishes a comprehensive framework to describe the transient quantum relaxation. Subjects: Quantum Physics (quant-ph) Cite as: arXiv:2604.21320 [quant-ph]   (or arXiv:2604.21320v1 [quant-ph] for this version)   https://doi.org/10.48550/arXiv.2604.21320 Focus to learn more Submission history From: Yan Li Zhou [view email] [v1] Thu, 23 Apr 2026 06:21:16 UTC (7,362 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?)