Density functional study of the electronic and vibrational properties of TiOCl

Abstract

We present the phonon spectrum of TiOCl computed using hybrid density functional theory (DFT). A complete analysis of the spectrum is performed for the space group Pmmn (high symmetry phase) and the space group P2_1/m (low symmetry phase), which is the symmetry of the spin-Peierls phase. We show that the nonlocal correlations present in the hybrid DFT approach are important for understanding the electron-lattice interactions in TiOCl. The computed frequencies compare well with those observed in Raman and infrared spectroscopy experiments and we identify the origin of an anomalous phonon observed in Raman spectroscopy. The relationship between relevant zone boundary phonons in the high symmetry phase and the zone center counterparts in the P2_1/m symmetry allow us to speculate about the origin of the spin-Peierls phonon.

arXiv comment9 pages, 14 figures, 5 tables

References in corpus (17)

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Cited by in corpus (8)

• Electronic structure of the two-dimensional Heisenberg antiferromagnet VOCl: a multi-orbital Mott insulator
• Determination of effective microscopic models for the frustrated antiferromagnets Cs${}_2$CuCl${}_4$ and Cs${}_2$CuBr${}_4$ by density functional methods
• Microscopic model for transitions from Mott to spin-Peierls insulator in TiOCl
• Momentum-resolved single-particle spectral function for TiOCl from a combination of density functional and variational cluster calculations
• Pressure-driven phase transitions in correlated systems
• Relevance of nonadiabatic effects in TiOCl
• Incommensurate spin Luttinger liquid phase in a model for the spin-Peierls materials TiOBr and TiOCl
• Phonon spectrum in the spin-Peierls phase of CuGeO${}_3$