Microscopic model for transitions from Mott to spin-Peierls insulator in TiOCl

  title={Microscopic model for transitions from Mott to spin-Peierls insulator in TiOCl},
  author={Yu-Zhong Zhang and Harald O. Jeschke and Roser Valent{\'i}},
  journal={Physical Review B},
On the basis of ab initio density functional theory (DFT) calculations, we derive the underlying microscopic model Hamiltonian for TiOCl, a unique system that shows two consecutive phase transitions from a Mott insulator to a spin-Peierls insulator through a structurally incommensurate phase. We show with our model that the presence of magnetic frustration in TiOCl leads to a competition with the spin-Peierls distortion, which results in the novel incommensurate phase. In addition, our… 
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