Quantum Statistical Theory of Superconductivity in MgB2
| Autor: | S. Fujita, A. Suzuki, Y. Takato |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Condensed Matter::Quantum Gases
010302 applied physics Superconductivity Physics Condensed matter physics 02 engineering and technology BCS theory 021001 nanoscience & nanotechnology 01 natural sciences law.invention symbols.namesake law Condensed Matter::Superconductivity Lattice (order) Quantum mechanics 0103 physical sciences Boltzmann constant symbols Cooper pair 0210 nano-technology Hamiltonian (quantum mechanics) Quantum Bose–Einstein condensate |
| Zdroj: | Journal of Modern Physics. :1546-1557 |
| ISSN: | 2153-120X 2153-1196 |
| DOI: | 10.4236/jmp.2016.712141 |
| Popis: | A quantum statistical theory of the superconductivity in MgB2 is developed regarding it as a member of the graphite intercalation compound. The superconducting temperature Tc for MgB2, C8K ≡ KC8, CaC6, are 39 K, 0.6 K, 11.5 K, respectively. The differences arise from the lattice structures. In the plane perpendicular to the c-axis, B’s form a honeycomb lattice with the nearest neighbour distance while Mg’s form a base-hexagonal lattice with the nearest neighbour distance above and below the B-plane distanced by . The more compact B-plane becomes superconducting due to the electron-phonon attraction. Starting with the generalized Bardeen- Cooper-Schrieffer (BCS) Hamiltonian and solving the generalized Cooper equation, we obtain a linear dispersion relation for moving Cooper pairs. The superconducting temperature Tc identified as the Bose-Einstein condensation temperature of the Cooper pairs in two dimensions is given by , where is the Cooper pair density, the Boltzmann constant. The lattices of KC8 and CaC6 are clearly specified. |
| Databáze: | OpenAIRE |
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