Article,
Local Ordering in the Pseudogap State of the High-Tc Superconductor Bi2Sr2CaCu2O8+delta
Science, 303 (5666): 1995--1998 (March 2004)
Abstract
We report atomic-scale characterization of the pseudogap state in
a high-Tc superconductor, Bi2Sr2CaCu2O8+delta. The electronic states
at low energies within the pseudogap exhibit spatial modulations
having an energy-independent incommensurate periodicity. These patterns,
which are oriented along the copper-oxygen bond directions, appear
to be a consequence of an electronic ordering phenomenon, the observation
of which correlates with the pseudogap in the density of electronic
states. Our results provide a stringent test for various ordering
scenarios in the cuprates, which have been central in the debate
on the nature of the pseudogap and the complex electronic phase diagram
of these compounds.
