Complete Fermi surface mapping of Bi2Sr2Can−1CunO2n+4(001) with n=1,2

The Fermi surface of Bi2Sr2CaCu2O8+x(001) and Bi2Sr2CuO6(001) has been mapped at nearly 6000 points in k space using angle-resolved photoemission at 300K. Bi2Sr2CaCu2O8+x(001) exhibits a shadow Fermi surface strongly suggesting short range antiferromagnetic correlations (P. Aebi et al., Phys. Rev. Lett. 72, 2757 (1994)). For its Ca free counter part the photoemission intensity at the Fermi level is weaker, reflecting the presence of only one Ca-O layer and the difference in doping. An estimation of the doping is given directly from the topology of the Fermi surface.