SHADOW BANDS IN OVERDOPED BI2SR2CACU2O8+X

We performed angle-resolved photoemission experiments on overdoped sin gle crystal Bi2Sr2CaCu2O8+x samples with Tc values as low as 55K and v ery narrow transitions as measured by AC susceptibility. The photoemis sion data indicate the presence of a ''shadow'' peak in the quasiparti cle spectral function A(omega) shifted by (pi, pi) from the convention al quasiparticle peak. The ratio of the shadow/quasiparticle peak ampl itudes 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.