»ã±¨±êÌâ (Title)£ºMottness physics in Nb3X8 (X=Cl, Br, I)£¨Nb3X8 (X=Cl, Br, I)ÖеÄĪÌØÎïÀí£©

»ã±¨ÈË (Speaker)£º½¯À¤ ×êÑÐÔ±£¨Öйú¿ÆѧԺÎïÀí×êÑÐËù£©

»ã±¨¹¦·ò (Time)£º2022Äê9ÔÂ21ÈÕ(ÖÜÈý) 10:00-12:00

»ã±¨µØÖ· (Place)£ºÐ£±¾²¿G309

Ô¼ÇëÈË(Inviter)£ºÕÅ D

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Recently, the 2-dimensional van der Waals materials Nb3Cl8 was found to be a Mott insulator. In this talk, we will discuss the correlation physics in Nb3X8 (X=Cl, Br, I). We find that the monolayers Nb3X8 are ideal systems close to the strong correlation limit. They can be described by a half-filled single band Hubbard model in which the ratio between the Hubbard, U, and the bandwidth, W, U/W ¡Ö 5 ¡« 10. Both Mott and magnetic transitions of the material are calculated by the slave boson mean field theory. Doping the Mott state, a dx2?y2+idxy superconducting pairing instability is found. We also construct a tunable bilayer Hubbard system for two sliding Nb3X8 layers. The bilayer system displays a crossover between the band insulator and Mott insulator.