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.
Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
A C
AC
Fang
L
L
Capriotti
D J
DJ
Scalapino
S A
SA
Kivelson
N
N
Kaneko
M
M
Greven
A
A
Kapitulnik