Quantum Fisher information density in infinite-size extended Ising chains Shu Qu, Hong-Guang Cheng, Chen Wu, Bin Guo and Zhao-Yu Sun Eur. Phys. J. B, 98 5 (2025) 101 Published online: 23 May 2025 DOI: 10.1140/epjb/s10051-025-00946-x