Nb₃Cl₈ Single-Band Mott Insulator

Ideal Hubbard Model Realization

Monolayer Nb₃Cl₈ realizes a Mott gap opened by strong correlations on a half-filled flat band, perfectly matching the single-band Hubbard model.

Gao, Shunye · Wang, Cuixiang · Yan, Shaohua · Han, Xin · Ji, Xuecong · Tao, Wei · Jingtong, Liu · Tiantian, Wang · Shuaikang, Yuan · Ge Xing, Qu · Ziyan, Chen · Yongzhao, Zhang · Huang, Jierui · Mojun, Pan · Peng, Shiyu · Hu, Yong · Li, Hang · Huang, Yaobo · Zhou, Hui · Meng, Sheng · Yang, Liu · Wang, Zhiwei · Yao, Yugui · Chen, Zhiguo · Shi, Ming · Ding, Hong · Yang, Huaixin · Jiang, Kun · Li, Yonglei · Lei, Hechang · Shi, Youguo · Weng, Hongming · Qian, Tian

Physical Review X 2023

Advantages

ARPES experiments observe a large gap

DFT calculations show a half-filled flat band at the Fermi level

DMFT calculations perfectly reproduce the experimentally observed gap

Bulk system undergoes a phase transition upon decreasing temperature, significantly enhancing interlayer coupling