On the electronic inhomogeneity of underdoped Bi2Sr2CaCu2O8+δ

Abstract Using scanning tunneling microscopy and spectroscopy (STM/STS), we investigated the spatial dependence of electronic structure in both the superconducting (SC) and pseudogap (PG) states of one underdoped Bi 2 Sr 2 CaCu 2 O 8 + δ (Bi2212). It is found that this sample shows rather homogeneous electronic states on a nanometer scale both below and above T c , supporting the contention that the spatially homogeneous electronic state exists in Bi2212. Furthermore, we emphasize that the electronic inhomogeneity reported previously [S.H. Pan, et al., Nature 413 (2001) 282; C. Howald, P. Fournier, A. Kapitulnik, Phys. Rev. B 64 (2001) 100504(R); T. Cren, et al., Phys. Rev. Lett. 84 (2000) 147; A. Hashimoto, et al., Phys. Rev. B 74 (2006) 064508] is associated with the incoherent electronic states in the antinodal regions on the Fermi surface and the superconductivity occurring on the “Fermi arc” is spatially homogeneous.