Many-body effects in TiSe2: Can GW describe an Excitonic Insulator?

M. Cazzaniga; H. Cercellier; M. Holzmann; C. Monney; P. Aebi; G. Onida; V. Olevano

Many-body effects in TiSe2: Can GW describe an Excitonic Insulator?

Strongly Correlated Electrons 2011-07-13 v3 Other Condensed Matter

Authors: M. Cazzaniga , H. Cercellier , M. Holzmann , C. Monney , P. Aebi , G. Onida , V. Olevano

Abstract

We present both theoretical ab initio GW and experimental angle-resolved photoemission (ARPES) and scanning tunneling (STS) spectroscopy results on TiSe2. With respect to the density-functional Kohn-Sham metallic picture, the many-body GW self-energy leads to a ~ 0.2 eV band gap insulator consistent with our STS spectra at 5 K. The band shape is strongly renormalized, with the top-of-valence moved towards a circle of points away from \Gamma, arising in a mexican hat feature typical of an excitonic insulator. Our calculations are in good agreement with experiment.

Keywords

TiSe2 GW approximation excitonic insulator angle-resolved photoemission spectroscopy scanning tunneling spectroscopy many-body effects

Cite

@article{arxiv.1103.2104,
  title  = {Many-body effects in TiSe2: Can GW describe an Excitonic Insulator?},
  author = {M. Cazzaniga and H. Cercellier and M. Holzmann and C. Monney and P. Aebi and G. Onida and V. Olevano},
  journal= {arXiv preprint arXiv:1103.2104},
  year   = {2011}
}

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5 pages 3 figures

Many-body effects in TiSe2: Can GW describe an Excitonic Insulator?

Abstract

Keywords

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