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Optical response of metallic and insulating VO2 calculated with the LDA approach

R. J. O. Mossanek·M. Abbate
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Abstract

We calculated the optical response of metallic and insulating VO2 using the LDA approach. The band structure calculation was based in the full-potential linear-muffin-tin method. The imaginary part of the dielectric function e2(w) is related to the different optical transitions. The Drude tail in the calculation of the metallic phase corresponds to intra-band d-d transitions. The calculation in the insulating phase is characterized by the transitions to the d||* band. The low frequency features, 0.0-5.0 eV, correspond to V 3d-V 3d transitions, whereas the high frequency structures, 5.0-12 eV, are related to O 2p-V 3d transitions. The calculation helps to explain the imaginary part of the dielectric function e2(w), as well as the electron-energy-loss and reflectance spectra. The results reproduce not only the energy position and relative intensity of the features in the spectra, but also the main changes across the metal-insulator transition and the polarization dependence. The main difference is a shift of about 0.6 eV in the calculation of the insulating phase. This discrepancy arises because the LDA calculation underestimates the value of the band gap.

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R. J. O. Mossanek, M. Abbate. 2006-08-21. Optical response of metallic and insulating VO2 calculated with the LDA approach. https://doi.org/10.1088/0953-8984%2F19%2F34%2F346225

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