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تسجيل مستخدم جديدIsotope effect and bond-stretching phonon anomaly in high-Tc cuprates
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We analyse a model where the anomalies of the bond-stretching LO phonon mode are caused by the coupling to electron dynamic response in the form of a damped oscillator and explore the possibility to reconstruct the spectrum of the latter from the phonon measurements. Preliminary estimates point to its location in the mid infrared region and we show how the required additional information can be extracted from the oxygen isotope effect on the phonon spectrum. The model predicts a significant measurable deviation from the standard value of the isotope effect even if the phonon frequency is far below the electron spectrum, provided the latter is strongly incoherent. In this regime, which corresponds to the mid infrared scenario, the phonon linewidth becomes a sensitive and informative probe of the isotope effect.
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We report the first measurement of the optical phonon dispersion in optimally doped single layer Bi2Sr1.6La0.4Cu2O6+delta using inelastic x-ray scattering. We found a strong softening of the Cu-O bond stretching phonon at about q=(0.25,0,0) from 76 t
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