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Many-body and Covalence Effects in the Polarization of Ferroelectric Perovskites

R. Resta·S. Sorella
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Abstract

The ferroelectric polarization of perovskite oxides is much larger than implied by displacement of static ionic charges. We use an explicitly correlated scheme to investigate the phenomenon; charge transport is evaluated as a geometric quantum phase. Both covalence and electron-electron interaction enhance polarization in the weakly correlated regime. At higher values of the electron-electron interaction, the system undergoes a transition from a band insulator to a Mott insulator: the static ionic charge is continuous across the transition, whereas the polarization is discontinuous. Above the transition, oxygen transports a positive charge.

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R. Resta, S. Sorella. 1994-11-11. Many-body and Covalence Effects in the Polarization of Ferroelectric Perovskites. https://arxiv.org/abs/cond-mat/9411050

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