Spatial Variations in the Fermi Surface of Bi-2212

In cuprate superconductors, scanning tunneling microscopy can be used to see variations in the Fermi surface on a nanometer length scale caused by doping inhomogeneity. Prior STM studies show that the local wavelength of the checkerboard, a weak charge modulation ascribed to antinodal Fermi surface nesting, varies with the size of the pseudogap in Bi$_2$Sr$_2$CuO$_{6+\delta}$ (Bi-2201) [1]. Here we report similar STM measurements in Bi-2212. We therefore confirm the local relationship between pseudogap energy and charge ordering wavevector in a second high-Tc superconductor.\\[4pt] [1] W. D. Wise, et al. Nature Physics 5, 213 (2009).