Mott Transition and Suppression of Orbital Fluctuations in Orthorhombic 3 d 1 Perovskites

University of Pavia, Ticinum, Lombardy, Italy
Physical Review Letters (Impact Factor: 7.73). 05/2004; 92(17):176403. DOI: 10.1103/PhysRevLett.92.176403
Source: PubMed

ABSTRACT Using ${t}_{2g}$ Wannier functions, a low-energy Hamiltonian is derived for orthorhombic $3{d}^{1}$ transition-metal oxides. Electronic correlations are treated with a new implementation of dynamical mean-field theory for noncubic systems. Good agreement with photoemission data is obtained. The interplay of correlation effects and cation covalency (${\mathrm{GdFeO}}_{3}$-type distortions) is found to suppress orbital fluctuations in ${\mathrm{LaTiO}}_{3}$ and even more in ${\mathrm{YTiO}}_{3}$, and to favor the transition to the insulating state.

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