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arXiv · 0810.2433

Momentum-resolved single-particle spectral function for TiOCl from a combination of density functional and variational cluster calculations

M. Aichhorn·T. Saha-Dasgupta·R. Valenti·S. Glawion·M. Sing·R. Claessen
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Abstract

We present results for the momentum-resolved single-particle spectral function of the low-dimensional system TiOCl in the insulating state, obtained by a combination of ab initio Density Functional Theory (DFT) and Variational Cluster (VCA) calculations. This approach allows to combine a realistic band structure and a thorough treatment of the strong correlations. We show that it is important to include a realistic two-dimensional band structure of TiOCl into the effective strongly-correlated models in order to explain the spectral weight behavior seen in angle-resolved photoemission (ARPES) experiments. In particular, we observe that the effect of the interchain couplings is a considerable redistribution of the spectral weight around the Gamma point from higher to lower binding energies as compared to a purely one-dimensional model treatment. Hence, our results support a description of TiOCl as a two-dimensional compound with strong anisotropy and also set a benchmark on the spectral features of correlated coupled-chain systems.

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M. Aichhorn, T. Saha-Dasgupta, R. Valenti, S. Glawion, M. Sing, R. Claessen. 2009-08-28. Momentum-resolved single-particle spectral function for TiOCl from a combination of density functional and variational cluster calculations. https://doi.org/10.1103/physrevb.80.115129

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