Gap-inhomogeneity-induced electronic states in superconducting Bi2Sr2CaCu2O(8+delta).
In this Letter, we analyze, using scanning tunneling spectroscopy, the density of electronic states in nearly optimally doped Bi2Sr2CaCu2O(8+delta) in zero magnetic field. Focusing on the superconducting gap, we find patches of what appear to be two different phases in a background of some average gap, one with a relatively small gap and sharp large coherence peaks and one characterized by a large gap with broad weak coherence peaks. We compare these spectra with calculations of the local density of states for a simple phenomenological model in which a 2xi0 x 2xi0 patch with an enhanced or suppressed d-wave gap amplitude is embedded in a region with a uniform average d-wave gap.
Fang
A C
AC
Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
Capriotti
L
L
Scalapino
D J
DJ
Kivelson
S A
SA
Kaneko
N
N
Greven
M
M
Kapitulnik
A
A