1. Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials College of Physics and Energy Fujian Normal University Fuzhou 350117 P. R. China
2. Fujian Provincial Collaborative Innovation Center for Advanced High‐Field Superconducting Materials and Engineering Fujian Normal University Fuzhou 350117 P. R. China
3. Institute of Physics Chinese Academy of Sciences Beijing 100190 P. R. China