Regensburg 2007 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 8: Superconductivity - Poster Session
TT 8.10: Poster
Montag, 26. März 2007, 14:00–17:45, Poster A
Quasiparticle approach to electronic Raman scattering in overdoped cuprates — •Wolfgang Prestel1, Bernhard Muschler1, Yoichi Ando2, Shimpei Ono2, and Rudi Hackl1 — 1Walther-Meissner-Institut, Garching — 2CRIEPI, Tokyo, Japan
High-Tc superconductors can be described as normal, though strongly correlated, metals
in the overdoped regime.
This implies that the conduction electrons in these materials can be viewed as independent quasiparticles
with defined momenta and a certain lifetime.
Here we explore the capability of this concept to explain the electronic Raman response in overdoped
cuprates.
The Raman response can be calculated in linear response theory using a generalized Kubo formula.
Owing to the k-dependence of the Raman vertices, selected by the polarizations of the
incoming and outgoing photons, different parts of the Brillouin zone can be projected out
independently.
In order to evaluate the Kubo formula one additionally needs the spectral function of the
quasiparticles.
In our model we assume a bandstructure and quasiparticle lifetimes as derived from ARPES experiments in order to calculate the Raman response for the
B1g and B2g symmetries.
Comparing model data and Raman spectra of La2−xSrxCO4 and Bi2Sr2CaCu2O8+δ,
we find remarkable agreement concerning symmetry and temperature dependences in both material systems.
This suggests that the quasiparticle approach is a reasonable starting point to explain carrier
dynamics in overdoped cuprates.
The project has been supported by the DFG under grant number Ha2071/3-1 via the Research Unit FOR538.