title: An intrinsic bond-centered electronic glass with unidirectional domains in underdoped cuprates.
abstract: Removing electrons from the CuO2 plane of cuprates alters the electronic correlations sufficiently to produce high-temperature superconductivity. Associated with these changes are spectral-weight transfers from the high-energy states of the insulator to low energies. In theory, these should be detectable as an imbalance between the tunneling rate for electron injection and extraction-a tunneling asymmetry. We introduce atomic-resolution tunneling-asymmetry imaging, finding virtually identical phenomena in two lightly hole-doped cuprates: Ca(1.88)Na(0.12)CuO(2)Cl2 and Bi2Sr2Dy(0.2)Ca(0.8)Cu2O(8+delta). Intense spatial variations in tunneling asymmetry occur primarily at the planar oxygen sites; their spatial arrangement forms a Cu-O-Cu bond-centered electronic pattern without long-range order but with 4a(0)-wide unidirectional electronic domains dispersed throughout (a(0): the Cu-O-Cu distance). The emerging picture is then of a partial hole localization within an intrinsic electronic glass evolving, at higher hole densities, into complete delocalization and highest-temperature superconductivity.
authors.affiliation: Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Kohsaka
authors.forename: C
authors.initials: C
authors.lastname: Taylor
authors.forename: K
authors.initials: K
authors.lastname: Fujita
authors.forename: A
authors.initials: A
authors.lastname: Schmidt
authors.forename: C
authors.initials: C
authors.lastname: Lupien
authors.forename: T
authors.initials: T
authors.lastname: Hanaguri
authors.forename: M
authors.initials: M
authors.lastname: Azuma
authors.forename: M
authors.initials: M
authors.lastname: Takano
authors.forename: H
authors.initials: H
authors.lastname: Eisaki
authors.forename: H
authors.initials: H
authors.lastname: Takagi
authors.forename: S
authors.initials: S
authors.lastname: Uchida
authors.forename: J C
authors.initials: JC
authors.lastname: Davis