Double Degeneracy and Jahn-Teller Effects in CMR Perovskites
نویسندگان
چکیده
Jahn-Teller (JT) electron-phonon coupling effects in the colossal magnetoresistance perovskite compounds La1−xAxMnO3 are investigated. Electronelectron correlations between two degenerate Mn eg orbitals are studied in the Gutzwiller approximation. The static JT distortion and antiadiabatic polaron effects are studied in a modified Lang-Firsov approximation. We find that (i) the electron or hole character of the charge carrier depends on the static JT distortion, and (ii) due to the two-component nature of the JT coupling, fluctuations in the JT distortion direction contribute to the charge transport in similar fashion as the local spins. 72.15.Gd,71.38+i,71.27+a Typeset using REVTEX
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