2026-07-14 中国科学院（CAS）
＜関連情報＞
- https://english.cas.cn/newsroom/research-news/202607/t20260714_1178374.shtml
- https://journals.aps.org/prl/abstract/10.1103/g8v5-rbq7
捕捉イオン系における特異点を介したエンタングルメント生成におけるエルミート速度限界の克服 Beating Hermitian Speed Limits for Entanglement Generation via Exceptional Points in a Trapped-Ion System
W. F. Yuan, B. B. Liu, N. Li, G. Y. Ding, W. Q. Ding, H. J. Du, J. C. Li, G. Chen, H. Jing et al.
Physical Review Letters Published: 28 May, 2026
DOI: https://doi.org/10.1103/g8v5-rbq7
Abstract
Entanglement generation is a cornerstone of quantum information science, yet its speed in Hermitian systems is fundamentally constrained by the coupling strength, a restriction known as the quantum speed limit. Here we demonstrate that this bound can be beaten by exploiting the unique topology of non-Hermitian systems near exceptional points (EPs). Using a pair of trapped ions, we engineer a parity-time symmetric Hamiltonian where the coalescence of eigenstates near the EP distorts the Hilbert space geometry, providing a shortcut for quantum state evolution. We observe that, as the system approaches the EP, the time required to generate a maximally entangled state is markedly reduced with respect to the limits imposed by the equivalent Hermitian interaction. We further uncover a fundamental physical trade-off whereby the acceleration of entanglement is intrinsically coupled to a reduction in the success probability, revealing the information cost of non-Hermitian speedup. Our results suggest that tailored dissipation, rather than being a source of decoherence, can serve as a powerful resource for accelerating quantum dynamics, offering a new paradigm for designing high-speed quantum gates and sensors in hardware-constrained platforms.
