Micro-Raman evidence for topological charge order across the superconducting dome of La2−xSrxCuO4

Abstract

The doping dependence of the micro-Raman spectra of high-quality La2−xSrxCuO4 microcrystals with x=0.0–0.45 has been investigated in the region 10–300K. The phonon at ∼100cm−1 of the orthorhombic phase shows a classical soft-mode behavior up to x=0.17, supporting its correlation with the low-temperature orthorhombic to high-temperature tetragonal transition. In the xx−yy polarization spectra of the superconducting concentrations new modes at ∼150 and 370cm−1 related to the symmetry breaking and a broad band at ∼280cm−1 are attributed to the charge ordering at temperatures well above Tc. At all temperatures studied a correlation has been found between the doping dependence of the transition temperature and the intensity of the bands at ∼150, ∼280, and ∼370cm−1, the intensity of the La∕Sr mode, and the asymmetry of the apex phonon.

Source-reported materials — not catalogue approval

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