Abstract Shake-up phenomena, rooted in the sudden approximation and many-body quantum dynamics, unveil critical characteristics of quantum systems, with wide-ranging applications in molecular spectroscopy and electronic structure studies. Here, this principle is extended to magnetic systems, and magnon shake-up structures and their relevance in generating and sensing magnon-magnon entanglement are demonstrated. This not only reveals new insights into shake-up phenomena and quantum magnetism but also paves the way for new opportunities in quantum technologies.
Azimi-Mousolou et al. (2026) studied this question.