Complete Fermi surface mapping of ${\mathrm{Bi}}_2$${\mathrm{Sr}}_2$${\mathrm{CaCu}}_2$${\mathrm{O}}_{8+\mathit{x}}$(001): Coexistence of short range antiferromagnetic correlations and metallicity in the same phase

The Fermi surface of ${\mathrm{Bi}}_2$ ${\mathrm{Sr}}_2$ ${\mathrm{CaCu}}_2$ ${\mathrm{O}}_{8+\mathit{x}}$(001) has been mapped at nearly 6000 points in k space using angle-resolved photoemission at 300 K. We observe both features that are in good agreement with the local density calculation of Massidda, Yu, and Freeman [Physica (Amsterdam) 158C, 251 (1988)] and others that are missing in the calculation. Among those missing, most importantly, we find a c(2×2) superstructure on the Fermi surface strongly suggesting short range antiferromagnetic correlations. It is remarkable that this is evident in the metallic state and in the Fermi surface itself.