An intrinsic bond-centered electronic glass with unidirectional domains in underdoped cuprates

作者:Kohsaka Y; Taylor C; Fujita K; Schmidt A; Lupien C; Hanaguri T; Azuma M; Takano M; Eisaki H; Takagi H; Uchida S; Davis J C*
来源:Science, 2007, 315(5817): 1380-1385.
DOI:10.1126/science.1138584

摘要

Removing electrons from the CuO(2) 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)Cl(2) and Bi(2)Sr(2)Dy(0.2)Ca(0.8)Cu(2)O(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.

  • 出版日期2007-3-9