Chen, Dongni
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Dongni Chen received her Ph.D. in Physics from the Institute of Theoretical Physics, Chinese Academy of Sciences, in 2022. She subsequently conducted postdoctoral research at Korea University and then joined the College of Science, Shantou University as a Lecturer in 2024. Her research focuses on nonequilibrium quantum dynamics in open quantum systems, including entanglement dynamics, dissipative phase transitions, and symmetry-related quantum phenomena.
Symmetry-Restoration Quantum Mpemba Effect in Weakly $\mathbb{Z}_2$-Symmetric Open Quantum Systems
- Speaker: Dongni Chen (Shantou University, China)
- Event: Quantum Technology Workshop 2026
The quantum Mpemba effect (QME) describes anomalous relaxation in which a state initially farther from equilibrium reaches the steady state faster than one initially closer to it. In this talk, I will present a symmetry-restoration QME in the weakly $\mathbb{Z}_2$-symmetric dissipative Dicke model, where the full Liouvillian preserves parity symmetry although individual quantum jumps do not. Using entanglement asymmetry to characterize parity restoration, we show that coherent-product states exhibit conventional relaxation, whereas cat-like superposition states display clear Mpemba behavior. A Liouvillian spectral analysis reveals that this anomalous relaxation originates from initial-state mode filtering: coherent superposition suppresses the slowest non-stationary Liouvillian mode, allowing faster decay channels to dominate the dynamics. The same mechanism operates in both the normal and superradiant regimes, while the low-lying Liouvillian spectrum determines the detailed relaxation profile. These results demonstrate that the quantum Mpemba effect can emerge without strong symmetry conservation and provide a new route for controlling nonequilibrium relaxation through initial-state engineering.