Superconducting Transition Temperature for Very Strong Coupling in the Antiadiabatic Limit of Eliashberg Equations
Autor: | Mikhail V. Sadovskii |
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Rok vydání: | 2021 |
Předmět: |
Coupling constant
Physics Physics and Astronomy (miscellaneous) Condensed matter physics Solid-state physics Phonon Fermi energy Lambda 01 natural sciences Omega 010305 fluids & plasmas Condensed Matter::Superconductivity 0103 physical sciences Strong coupling Limit (mathematics) 010306 general physics |
Zdroj: | JETP Letters. 113:581-585 |
ISSN: | 1090-6487 0021-3640 |
DOI: | 10.1134/s0021364021090034 |
Popis: | It is shown that the famous Allen–Dynes asymptotic limit for the superconducting transition temperature in the very strong coupling region $${{T}_{{\text{c}}}} > \frac{1}{{2\pi }}\sqrt \lambda {{\Omega }_{0}}$$ (where $$\lambda \gg 1$$ is the Eliashberg–McMillan electron–phonon coupling constant and $${{\Omega }_{0}}$$ is the characteristic frequency of phonons) in the antiadiabatic limit of Eliashberg equations $${{\Omega }_{0}}{\text{/}}D \gg 1$$ ( $$D \sim {{E}_{{\text{F}}}}$$ is the half-width of the conduction band and EF is the Fermi energy) is replaced by $${{T}_{{\text{c}}}} > {{(2{{\pi }^{4}})}^{{ - 1/3}}}{{(\lambda D\Omega _{0}^{2})}^{{1/3}}}$$ , with the upper limit $${{T}_{{\text{c}}}} < \frac{2}{{{{\pi }^{2}}}}\lambda D$$ . |
Databáze: | OpenAIRE |
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