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Double Degeneracy and Jahn-Teller Effects in CMR Perovskites

Jun Zang·A. R. Bishop·H. Roder
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Abstract

Jahn-Teller (JT) electron-phonon coupling effects in the colossal magnetoresistance perovskite compounds $La_{1-x}A_xMnO_3$ are investigated. Electron-electron correlations between two degenerate Mn $e_g$ 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.

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Jun Zang, A. R. Bishop, H. Roder. 1995-07-24. Double Degeneracy and Jahn-Teller Effects in CMR Perovskites. https://doi.org/10.1103/physrevb.53.r8840

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