Accelerating relaxation through Liouvillian exceptional point

Zhou, Yan-Li; Yu, Xiao-Die; Wu, Chun-Wang; Li, Xie-Qian; Zhang, Jie; Li, Weibin; Chen, Ping-Xing

Abstract

We investigate speeding up of relaxation of Markovian open quantum systems with the Liouvillian exceptional point (LEP), where the slowest decay mode degenerate with a faster decay mode. The degeneracy significantly increases the gap of the Liouvillian operator, which determines the timescale of such systems in converging to stationarity, and hence accelerates the relaxation process. We explore an experimentally relevant three level atomic system, whose eigenmatrices and eigenspectra are obtained completely analytically. This allows us to gain insights in the LEP and examine respective dynamics with details. We illustrate that the gap can be further widened through Floquet engineering, which further accelerates the relaxation process. Finally, we extend this approach to analyze laser cooling of trapped ions, where vibrations (phonons) couple to the electronic states. An optimal cooling condition is obtained analytically, which agrees with both existing experiments and numerical simulations. Our study provides analytical insights in understanding LEP, as well as in controlling and optimizing dissipative dynamics of atoms and trapped ions.

Citation

Zhou, Y., Yu, X., Wu, C., Li, X., Zhang, J., Li, W., & Chen, P. (2023). Accelerating relaxation through Liouvillian exceptional point. Physical Review Research, 5(4), Article 043036. https://doi.org/10.1103/PhysRevResearch.5.043036

• Journal Article Type: Article
• Acceptance Date: Sep 23, 2023
• Online Publication Date: Oct 11, 2023
• Publication Date: 2023-10
• Deposit Date: Sep 25, 2023
• Publicly Available Date: Oct 16, 2023
• Journal: Physical Review Research
• Electronic ISSN: 2643-1564
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 5
• Issue: 4
• Article Number: 043036
• DOI: https://doi.org/10.1103/PhysRevResearch.5.043036
• Keywords: Open quantum systems & decoherence; Quantum control
• Public URL: https://nottingham-repository.worktribe.com/output/25373711