Naslov
Raman modes and strong intraplanar oxygen-oxygen charge fluctuations in YBa/sub 2/Cu/sub 3/O/sub 7/

Autori
Barišić, Slaven ; Kupčić, Ivan ; Batistić, Ivo

Izvornik
International Journal of Modern Physics B (0217-9792) 3 (1989), 12; 2051-2063

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
high temperature superconductor; transition temperature; O-O charge fluctuations; electron-phonon couplings

Sažetak
It is shown that symmetric and antisymmetric (340 cm/sup -1/) Raman modes are strongly coupled respectively to the intracell, intraplanar oxygen-copper and oxygen-oxygen charge fluctuations in YBa/sub 2/Cu/sub 3/O/sub 7/. The dominant coupling arises from the variations of the crystal field with deformations. The anomalous behavior of the 340 cm/sup -1/ mode is thus attributed to the corresponding behaviour of the in-plane oxygen-oxygen charge correlation function. The symmetric modes are continuous at T/sub c/, and this contrast is examined within the existing theories. It appears that the Emery model is a suitable starting point for the explanation of the Raman mode behavior. The increase of the ep coupling from one high T/sub c/ family to another turns out to correlate with increase of T/sub c/

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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