Naslov
Polaron tunnelling as a mechanism for the double-well anharmonicity of the axial oxygen in YBa_2Cu_3O_7

Autori
Mustre de Leon, Jose ; Batistić, Ivo ; Trugman, Stuart A. ; Bishop, Alan R. ; Conradson, S.D.

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Proceedings of the Conference. Lattice Effects in High-T_c Superconductors / Bar-Yam Y ; Egami T ; Mustre-de-Leon J ; Bishop AR. - Singapur : World Scientific Publishing, 1992, 163-170

Skup
Lattice Effects in High-T_c Superconductors

Mjesto i datum
Santa Fe (NM), Sjedinjene Američke Države, 13.01.1992. - 15.01.1992

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
high temperature superconductivity; polaron tunnelling; infrared mode; double-well anharmonicity; exact diagonalizatio

Sažetak
The authors present exact diagonalization results of an electron-phonon model Hamiltonian for the O(4)-Cu(1)-O(4) cluster in YBa/sub 2/Cu/sub 3/O/sub 7/. For large enough electron-infrared phonon coupling the motion of holes and ions becomes strongly correlated, i.e., polaronic, leading to a double-well structure for the infrared mode, as encountered in X-ray-absorption fine structure. In contrast, the associated Raman mode shows a single-well behavior even for large electron-Raman phonon coupling. The appearance of polarons accompanies nonadiabatic behavior yielding optical spectroscopy predictions differing from those obtained from anharmonic lattice dynamics models.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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