Abstract

We performed angle-resolved photoemission experiments on overdoped single crystal Bi2Sr2CaCu2O8+x samples with Tc values as low as 55K and very narrow transitions as measured by AC susceptibility. The photoemission data indicate the presence of a ''shadow'' peak in the quasiparticle spectral function A(omega) shifted by (pi, pi) from the conventional quasiparticle peak. The ratio of the shadow/quasiparticle peak amplitudes strongly increases with the binding energy. This is consistent with the idea that the shadow peak is not a structural replica of the quasiparticle peak, but rather a maximum in a spectral function which can exist due to interaction with spin fluctuations peaked at (pi, pi). (C) 1997 Published by Elsevier Science Ltd.

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