This work is based on multiple collaboration among national university in S. Korea and national laboratory in S. Korea and USA. This is initiated by CNMS user proposal back in 2019. C. Rouleau, J. Keum, and D. Pajerowski encouraged to finish this work. Also, Jaekwang Lee (PNU) and Sang Don Bu (JNU) helped DFT calculation and ferroelectric measurements. Thank you!