[2] Chiba Univ, Grad Sch Adv Integrat Sci, Chiba 2638522, Japan
来源:
PHYSICAL REVIEW B
|
2013年
/
87卷
/
03期
关键词:
TMSE0.45TE0.55;
FERROMAGNETISM;
INSULATOR;
D O I:
10.1103/PhysRevB.87.035121
中图分类号:
T [工业技术];
学科分类号:
08 ;
摘要:
Using the band structure calculation and mean-field analysis of the derived three-chain Hubbard model with phonon degrees of freedom, we discuss the origin of the orthorhombic-to-monoclinic phase transition of the layered chalcogenide Ta2NiSe5. We show that the Bose-Einstein condensation of excitonic electron-hole pairs cooperatively induces the instability of the phonon mode at momentum q -> 0 in the quasi-one-dimensional Ta-NiSe-Ta chain, resulting in the structural phase transition of the system. The calculated single-particle spectra reproduce the deformation of the band structure observed in the angle-resolved photoemission spectroscopy experiment. DOI: 10.1103/PhysRevB.87.035121