Correlation-assisted phonon softening and the orbital-selective Peierls transition in VO
To explore the driving mechanisms of the metal-insulator transition (MIT) and the structural
transition in VO 2, we have investigated phonon dispersions of rutile VO 2 (R-VO 2) in the
density functional theory (DFT) and the DFT+ U (U: Coulomb correlation) band calculations.
We have found that the phonon softening instabilities occur in both cases, but the softened
phonon mode only in the DFT+ U describes properly both the MIT and the structural
transition from R-VO 2 to monoclinic VO 2 (M 1-VO 2). The present ab initio phonon …
transition in VO 2, we have investigated phonon dispersions of rutile VO 2 (R-VO 2) in the
density functional theory (DFT) and the DFT+ U (U: Coulomb correlation) band calculations.
We have found that the phonon softening instabilities occur in both cases, but the softened
phonon mode only in the DFT+ U describes properly both the MIT and the structural
transition from R-VO 2 to monoclinic VO 2 (M 1-VO 2). The present ab initio phonon …
To explore the driving mechanisms of the metal-insulator transition (MIT) and the structural transition in VO, we have investigated phonon dispersions of rutile VO (-VO) in the density functional theory (DFT) and the DFT (: Coulomb correlation) band calculations. We have found that the phonon softening instabilities occur in both cases, but the softened phonon mode only in the DFT describes properly both the MIT and the structural transition from -VO to monoclinic VO (M-VO). The present ab initio phonon dispersion calculations clearly demonstrate that the Coulomb correlation effect plays an essential role of assisting the Peierls transition in -VO and producing the spin-Peierls ground state in M-VO.
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