Anomalous metallic state of Cu$_{0.07}$TiSe$_2$: an optical spectroscopy study

G. Li; W. Z. Hu; J. Dong; D. Qian; D. Hsieh; M. Z. Hasan; E. Morosan; R. J. Cava; N. L. Wang

doi:10.1103/PhysRevLett.99.167002

Anomalous metallic state of Cu$_{0.07}$TiSe$_2$: an optical spectroscopy study

Superconductivity 2009-11-13 v1 Strongly Correlated Electrons

Authors: G. Li , W. Z. Hu , J. Dong , D. Qian , D. Hsieh , M. Z. Hasan , E. Morosan , R. J. Cava , N. L. Wang

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Abstract

We report an optical spectroscopy study on the newly discovered superconductor Cu $_{0.07}$ TiSe $_2$ . Consistent with the development from a semimetal or semiconductor with a very small indirect energy gap upon doping TiSe $_2$ , it is found that the compound has a low carrier density. Most remarkably, the study reveals a substantial shift of the "screened" plasma edge in reflectance towards high energy with decreasing temperature. This phenomenon, rarely seen in metals, indicates either a sizeable increase of the conducting carrier concentration or/and a decrease of the effective mass of carriers with reducing temperature. We attribute the shift primarily to the later effect.

Keywords

anomalous metallic state Cu$_{0.07}$TiSe$_2$ optical spectroscopy superconductor plasma edge carrier density effective mass reflectance

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@article{arxiv.0706.4455,
  title  = {Anomalous metallic state of Cu$_{0.07}$TiSe$_2$: an optical spectroscopy study},
  author = {G. Li and W. Z. Hu and J. Dong and D. Qian and D. Hsieh and M. Z. Hasan and E. Morosan and R. J. Cava and N. L. Wang},
  journal= {arXiv preprint arXiv:0706.4455},
  year   = {2009}
}

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4 figures, 4+ pages

Anomalous metallic state of Cu$_{0.07}$TiSe$_2$: an optical spectroscopy study

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