A layering model for superconductivity in the borocarbides
| Autor: | Raimundo R. dos Santos, M. El Massalami, Thereza Paiva |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Physics
Superconductivity Strongly Correlated Electrons (cond-mat.str-el) Condensed matter physics Hubbard model Condensed Matter - Superconductivity Superlattice FOS: Physical sciences Condensed Matter Physics Drude model Band offset Superconductivity (cond-mat.supr-con) Condensed Matter - Strongly Correlated Electrons Condensed Matter::Superconductivity Pairing General Materials Science Metal–insulator transition Electronic band structure |
| Zdroj: | Journal of Physics: Condensed Matter. 15:7917-7924 |
| ISSN: | 1361-648X 0953-8984 |
| Popis: | We propose a superlattice model to describe superconductivity in layered materials, such as the borocarbide families with the chemical formul\ae\ $RT_2$B$_2$C and $RT$BC, with $R$ being (essentially) a rare earth, and $T$ a transition metal. We assume a single band in which electrons feel a local attractive interaction (negative Hubbard-$U$) on sites representing the $T$B layers, while U=0 on sites representing the $R$C layers; the multi-band structure is taken into account minimally through a band offset $\epsilon$. The one-dimensional model is studied numerically through the calculation of the charge gap, the Drude weight, and of the pairing correlation function. A comparison with the available information on the nature of the electronic ground state (metallic or superconducting) indicates that the model provides a systematic parametrization of the whole borocarbide family. Comment: 4 figures |
| Databáze: | OpenAIRE |
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