Ab Initio Calculation of Impurity Effects in Copper Oxide Materials

Abstract

We describe a method for calculating, within density functional theory, the electronic structure associated with typical defects which substitute for Cu in the CuO2 planes of high-Tc superconducting materials. The focus is primarily on Bi2Sr2CaCu2O8, the material on which most STM measurements of impurity resonances in the superconducting state have been performed. The magnitudes of the effective potentials found for Zn, Ni and vacancies on the in-plane Cu sites in this host material are remarkably consistent with phenomenological fits of potential scattering models to STM resonance energies. The effective potential ranges are quite short, of order 1 A with weak long range tails, in contrast to some current models of extended potentials which attempt to fit STM data. For the case of Zn and Cu vacancies, the effective potentials are strongly repulsive, and states on the impurity site near the Fermi level are simply removed. The local density of states (LDOS) just above the impurity is nevertheless found to be a maximum in the case of Zn and a local minimum in case of the vacancy, in agreement with experiment. The Zn and Cu vacancy patterns are explained as due to the long-range tails of the effective impurity potential at the sample surface. The case of Ni is richer due to the Ni atom's strong hybridization with states near the Fermi level; in particular, the short range part of the potential is attractive, and the LDOS is found to vary rapidly with distance from the surface and from the impurity site. We propose that the current controversy surrounding the observed STM patterns can be resolved by properly accounting for the effective impurity potentials and wave-functions near the cuprate surface. Other aspects of the impurity states for all three species are discussed.

arXiv comment37 pp. pdf including figures, submitted to Phys. Rev. B

References in corpus (14)

• Imaging the Effects of Individual Zinc Impurity Atoms on Superconductivity in Bi2Sr2CaCu2O8+delta
• Effect of chemical inhomogeneity in the bismuth-based copper oxide superconductors
• Interplay of magnetism and high-Tc superconductivity at individual Ni impurity atoms in Bi2Sr2CaCu2O8+d
• Phenomenological Models for the Gap Anisotropy of Bi-2212 as Measured by ARPES
• Impurity-Induced Virtual Bound States in d-Wave Superconductors
• Impurity-Induced Bound Excitations on the Surface of Bi2Sr2CaCu2O8
• Impurity in a d-wave superconductor: Kondo effect and STM spectra
• Influence of Gap Extrema on the Tunneling Conductance Near an Impurity in an Anisotropic Superconductor
• Impurity states and interlayer tunneling in high temperature superconductors
• Theory of Thermal Conductivity in YBa_2Cu_3O_{7-δ}
• States of Local Moment Induced by Nonmagnetic Impurities in Cuprate Superconductors
• Effect of unitary impurities in non-STM-types of tunneling in high-T_c superconductors
• Local Moment Formation in the Superconducting State of a Doped Mott Insulator
• Van Hove features in BSCCO(2212) and effective parameters for Ni impurities inferred from STM spectra

Cited by in corpus (19)

• Lattice symmetry breaking in cuprate superconductors: Stripes, nematics, and superconductivity
• Defects in correlated metals and superconductors
• Anomalous Transport Phenomena in Fermi Liquids with Strong Magnetic Fluctuations
• Interpretation of scanning tunneling quasiparticle interference and impurity states in cuprates
• First-principles calculation of transition-metal impurities in LaFeAsO
• Effects of cobalt doping and three-dimensionality in $BaF{e}_{2}A{s}_2$
• Visualization of atomic-scale phenomena in superconductors: application to FeSe
• Local electronic structure near oxygen dopants in BSCCO-2212: a window on the high-Tc pair mechanism?
• Andreev states near short-ranged pairing potential impurities
• Structure of BSCCO supermodulation from ab initio calculations
• Universality of scanning tunneling microscopy in cuprate superconductors
• Insensitivity of superconductivity to disorder in the cuprates
• Impurity-induced frustration in correlated oxides
• Mechanism of metallization and superconductivity suppression in YBa${}_2($Cu${}_{0.97}$Zn${}_{0.03}{)}_3$O${}_{6.92}$ revealed by ${}^{67}$Zn NQR
• Theory of Friedel oscillations in monolayer graphene and group-VI dichalcogenides in a magnetic field
• Impurity-induced frustration: low-energy model of diluted oxides
• Percolative Mott insulator-metal transition in doped Sr${}_2$IrO${}_4$
• Extinction of impurity resonances in large-gap regions of inhomogeneous d-wave superconductors
• First principle prediction of structural distortions in the cuprates and their impact on the electronic structure