Piezoelectric‐Metal Phononic Crystal Enabling GHz Tunable Ultrahigh Q Quasi‐BIC Mode (Adv. Sci. 6/2026). - Xu, Xuankai; Li, Jiawei; Wang, Ruoyu; Xiong, Ruihong; Wang, Yiwei; Shen, Xiaoqin; Wu, Tao (Advanced Science, 2026)