Correlation between Raman sum and optical conductivity sum in La sub(2-x)Sr sub(x)CuO sub(4)

• Published in: Journal of physics. Condensed matter Vol. 25; no. 41; pp. 1 - 10
• Main Authors: Sugai, S, Nohara, J, Shiozaki, R, Muroi, T, Takayanagi, Y, Hayamizu, N, Takenaka, K, Okazaki, K
• Format: Journal Article
• Language: English
• Published: 16.10.2013
• Subjects: Coherence; Condensed matter; COPPER OXIDE; Correlation; Dispersions; ELECTRICAL CONDUCTIVITY; MAGNETIC PROPERTIES; Segments; SPECTRA; Spin waves; Symmetry
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/25/41/415701

In a strongly correlated electron system, the single-particle spectral function changes into a coherent peak and incoherent humps which extend over 1 eV. The incoherent parts lose the symmetry and k dependence, so that the Raman spectra with different symmetries become identical and they are expressed by the optical conductivity. We found that the B sub(1g) and B sub(2g) spectra in La sub(2-x)Sr sub(x)CuO sub(4) become identical above 2000 cm super(-1) in the underdoped phase, if Fleury-Loudon type B sub(1g) two-magnon scattering is removed. The first Raman susceptibility moment correlates with the generalized optical conductivity moment. The good correlation arises from the incoherent states of a hump from 1000 to 4000 cm super(-1). The hump is the only structure of the incoherent electronic states in the mid-infrared absorption spectra below 1.4 eV at low carrier densities. The energy is twice the separated dispersion segments of the spin wave in the k[bottom] stripe direction. The incoherent state is formed by the magnetic excitations created by the hole hopping in the antiferromagnetic spin stripes in the real space picture.