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Full-Text Articles in Physics
Origin Of The Electron-Hole Asymmetry In The Scanning Tunneling Spectrum Of The High-Temperature Bi₂Sr₂Cacu₂O₈+Δ Superconductor, Jouko Nieminen, Hsin Lin, R. Markiewicz, A. Bansil
Origin Of The Electron-Hole Asymmetry In The Scanning Tunneling Spectrum Of The High-Temperature Bi₂Sr₂Cacu₂O₈+Δ Superconductor, Jouko Nieminen, Hsin Lin, R. Markiewicz, A. Bansil
Robert Markiewicz
We have developed a material specific theoretical framework for modeling scanning tunneling spectroscopy (STS) of high-temperature superconducting materials in the normal as well as the superconducting state. Results for Bi₂Sr₂CaCu₂O₈₊δ (Bi2212) show clearly that the tunneling process strongly modifies the STS spectrum from the local density of states of the dₓ2₋y2 orbital of Cu. The dominant tunneling channel to the surface Bi involves the dₓ2₋y2 orbitals of the four neighboring Cu atoms. In accord with experimental observations, the computed spectrum displays a remarkable asymmetry between the processes of electron injection and extraction, which arises from contributions of Cu dz2 and …
Origin Of The Electron-Hole Asymmetry In The Scanning Tunneling Spectrum Of The High-Temperature Bi₂Sr₂Cacu₂O₈+Δ Superconductor, Jouko Nieminen, Hsin Lin, R. S. Markiewicz, A. Bansil
Origin Of The Electron-Hole Asymmetry In The Scanning Tunneling Spectrum Of The High-Temperature Bi₂Sr₂Cacu₂O₈+Δ Superconductor, Jouko Nieminen, Hsin Lin, R. S. Markiewicz, A. Bansil
Hsin Lin
We have developed a material specific theoretical framework for modeling scanning tunneling spectroscopy (STS) of high-temperature superconducting materials in the normal as well as the superconducting state. Results for Bi₂Sr₂CaCu₂O₈₊δ (Bi2212) show clearly that the tunneling process strongly modifies the STS spectrum from the local density of states of the dₓ2₋y2 orbital of Cu. The dominant tunneling channel to the surface Bi involves the dₓ2₋y2 orbitals of the four neighboring Cu atoms. In accord with experimental observations, the computed spectrum displays a remarkable asymmetry between the processes of electron injection and extraction, which arises from contributions of Cu dz2 and …
Angle-Resolved Photoemission-Study Of (100), (110), And (111) Surfaces Of Cu0.9a10.1: Bulk And Surface Electronic-Structure Of The Alloy, H. Asonen, M. Lindroos, M. Pessa, P. Prasad, R. Rao, A. Bansil
Angle-Resolved Photoemission-Study Of (100), (110), And (111) Surfaces Of Cu0.9a10.1: Bulk And Surface Electronic-Structure Of The Alloy, H. Asonen, M. Lindroos, M. Pessa, P. Prasad, R. Rao, A. Bansil
Arun Bansil
We present angle-resolved photoemission spectra from the low-index faces of CuAl single crystals using 16.85- and 21.22-eV radiation, together with the computed bulk electronic structure of the alloy within the framework of the muffin-tin coherent-potential approximation (CPA). The d-band complex of Cu is found to suffer shifts of less than 0.1 eV on alloying, whereas the states of s-p symmetry are lowered in energy by as much as on the order of 1 eV. The dispersion curve of the uppermost valence band is measured and with the extrapolation of this curve to the Fermi energy (EF), the Fermi-surface radii along …
Electronic Structure Of Cu₇₅Au₂₅ Disordered Alloy, E. Arola, R. S. Rao, A. Salokatve, A. Bansil
Electronic Structure Of Cu₇₅Au₂₅ Disordered Alloy, E. Arola, R. S. Rao, A. Salokatve, A. Bansil
Arun Bansil
We present angle-resolved uv photoemission (normal emission) measurements from the (100) and (111) surfaces of Cu₇₅Au₂₅ alloy single crystals, together with fully relativistic as well as nonrelativistic Korringa-Kohn-Rostoker coherent-potential-approximation calculations of complex energy bands and densities of states. A good overall accord is found between the measurements and theoretical predictions with regard to the shifts and smearings of various bulk states in the alloy. The characteristic effects of alloying Au on the electronic structure of Cu are identified; the principal Au-induced feature is 2.5 eV wide, and appears 3 eV below the Cu-derived d band in the alloy; this feature …
Origin Of The Electron-Hole Asymmetry In The Scanning Tunneling Spectrum Of The High-Temperature Bi₂Sr₂Cacu₂O₈+Δ Superconductor, Jouko Nieminen, Hsin Lin, R. S. Markiewicz, A. Bansil
Origin Of The Electron-Hole Asymmetry In The Scanning Tunneling Spectrum Of The High-Temperature Bi₂Sr₂Cacu₂O₈+Δ Superconductor, Jouko Nieminen, Hsin Lin, R. S. Markiewicz, A. Bansil
Arun Bansil
We have developed a material specific theoretical framework for modeling scanning tunneling spectroscopy (STS) of high-temperature superconducting materials in the normal as well as the superconducting state. Results for Bi₂Sr₂CaCu₂O₈₊δ (Bi2212) show clearly that the tunneling process strongly modifies the STS spectrum from the local density of states of the dₓ2₋y2 orbital of Cu. The dominant tunneling channel to the surface Bi involves the dₓ2₋y2 orbitals of the four neighboring Cu atoms. In accord with experimental observations, the computed spectrum displays a remarkable asymmetry between the processes of electron injection and extraction, which arises from contributions of Cu dz2 and …
Electronic Structure Of Copper-Rich Copper-Palladium Alloys, R. S. Rao, A. Bansil, H. Asonen, M. Pessa
Electronic Structure Of Copper-Rich Copper-Palladium Alloys, R. S. Rao, A. Bansil, H. Asonen, M. Pessa
Arun Bansil
In considering the electronic structure of (Cu-rich) CuPd alloys, we present computations of complex-energy bands and average densities of states together with the angle-resolved photoemission spectra from the (100), (111), and (110) surfaces of Cu₉₅Pd₅ and Cu₈₅Pd₁₅ single crystals. The impurity spectrum in CuPd is found to be dominated by two quite-well-separated Pd-derived impurity bands and differs sharply from the case of CuNi or AgPd systems, where only a single Ni- or Pd-related impurity structure appears in the alloy. Extensive comparisons between the theory and experiment are carried out with regard to the positions and halfwidths of the Pd-induced impurity …