Lattice Effect of Strong Electron Correlation: Implication for Ferroelectricity and Superconductivity

Science  03 Sep 1993:
Vol. 261, Issue 5126, pp. 1307-1310
DOI: 10.1126/science.261.5126.1307


Much theoretical work has been devoted to understanding the role of strong electron correlations in high-temperature superconductivity mainly through magnetic interactions, but the possible role of electron correlation in ferroelectricity of metal oxides has not received attention. Diagonalization of a simple many-body, tight-binding Hamiltonian shows that the electron-lattice interaction is dramatically enhanced in some cases by strong electron correlation because of deformation-induced charge transfer. This effect may be closely related to ferroelectricity and superconductivity in transition metal oxides.