Anomalous multi-order Raman scattering in LaMnO_3: a signature of a quantum lattice effect in a Jahn-Teller crystal

Autor:	Kovaleva, N. N., Kusmartseva, O. E., Kugel, K. I., Maksimov, A. A., Nuzhnyy, D., Balbashov, A. M., Demikhov, E. I., Dejneka, A., Trepakov, V. A., Kusmartsev, F. V., Stoneham, A. M.
Rok vydání:	2014
Předmět:	Condensed Matter - Strongly Correlated Electrons
Zdroj:	J. Phys.: Condens. Matter 25 (2013) 155602
Druh dokumentu:	Working Paper
DOI:	10.1088/0953-8984/25/15/155602
Popis:	The multi-order Raman scattering is studied up to a fourth order for a detwinned LaMnO_3 crystal. Based on a comprehensive data analysis of the polarisation-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 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. Comment: 12 pages, 4 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1407.1409 Zobrazit plný text záznamu View this record from Arxiv