Origin of the shadow Fermi surface in Bi-based cuprates
  We used angle-resolved photoemission spectroscopy to study the shadow Fermi surface in one layer Bi2Sr1.6La0.4CuO6+delta and two layer (Bi,Pb)2Sr2CaCu2O8+delta. We find the shadow band to have the same peakwidth and dispersion as the main band. In addition, the shadow band/main band intensity ratio is found to be binding energy independent. Consequently, it is concluded that the shadow bands in Bi-based HTSC do not originate from antiferromagnetic interactions but have a structural origin. 
A. Koitzsch, S. V. Borisenko, A. A. Kordyuk, T. K. Kim, M. Knupfer, J.   Fink, M. S. Golden, W. Koops, H. Berger, B. Keimer,...