Real-space fluctuations of effective exchange integrals in high-Tc cuprates

Abstract

We present ab-initio calculations of effective magnetic exchange, $J$, as well as Hubbard parameters ($t$, $U$ and $\delta \epsilon$) as a function of the local distribution of doping atoms for the high-$T_c$ superconducting $(\mathrm{C}{\mathrm{a}}_{\mathrm{x}}\mathrm{L}{\mathrm{a}}_{1-\mathrm{x}})(\mathrm{B}{\mathrm{a}}_{1.75-\mathrm{x}}\mathrm{L}{\mathrm{a}}_{0.25+\mathrm{x}})\mathrm{C}{\mathrm{u}}_3{\mathrm{O}}_{\mathrm{y}}$ family. We found that both the exchange and the energies of the magnetic orbitals are strongly dependant on the local dopant distribution, both through the induced modification of the apical oxygen location and of the induced local electrostatic potential. The $J$ real-space map, for a random distribution of dopants, positively compares with observed STS gap inhomogeneity maps. Similarly, the orbital energy fluctuations induce weak charge inhomogeneities on copper sites, that can be positively compared with the observed LDOS inhomogeneities. These results clearly support an extrinsic origin of both the gap inhomogeneities and LDOS.

References in corpus (8)

• Discovery of microscopic electronic inhomogeneity in the high-Tc superconductor Bi2Sr2CaCu2O8+x
• Imaging the granular structure of high-Tc superconductivity in underdoped Bi2Sr2CaCu2O8+x
• The Physics Behind High-Temperature Superconducting Cuprates: The "Plain Vanilla" Version Of RVB
• Inherent Inhomogeneities in Tunneling Spectra of BSCCO Crystals in the Superconducting State
• Anomalous superconductivity and its competition with antiferromagnetism in doped Mott insulators
• Fast calculation of the electrostatic potential in ionic crystals by direct summation method
• A magnetic analog of the isotope effect in cuprates
• The Structure and a Bond-Valence-Sum Study of the 1-2-3 Superconductors CLBLCO and YBCO

Cited by in corpus (5)

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• Real space inhomogeneities in high temperature superconductors: the perspective of two-component model
• 17O-NMR Knight shift study of the interplay between superconductivity and pseudogap in (Ca_xLa_{1-x})(Ba_{1.75 - x}La_{0.25 + x})Cu_3O_y
• Enhanced Pairing Correlations near Oxygen Dopants in Cuprate Superconductors