Anomalous multi-order Raman scattering in LaMnO3: a signature of quantum lattice effects in a Jahn-Teller crystal
Abstract
The multi-order Raman scattering is studied up to fourth order for a detwinned LaMnO3 crystal. Based on a comprehensive data analysis of the polarization-dependent Raman spectra, we show that the anomalous features in the multi-order scattering could be the sidebands on the low-energy mode at about 25 cm-1. We suggest that this low-energy mode stems from the tunneling transition between the potential energy minima arising near the Jahn-Teller Mn3+ ion due to the lattice anharmonicity and that the multi-order scattering is activated by this low-energy electronic motion. The sidebands are dominated by the oxygen contribution to the phonon density-of-states, however, there is an admixture of an additional component, which may arise from coupling between the low-energy electronic motion and the vibrational modes.
- Publication:
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Journal of Physics Condensed Matter
- Pub Date:
- April 2013
- DOI:
- 10.1088/0953-8984/25/15/155602
- arXiv:
- arXiv:1407.1409
- Bibcode:
- 2013JPCM...25o5602K
- Keywords:
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- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 12 pages, 4 figures