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Nonadiabatic superconductivity in a Li-intercalated hexagonal boron nitride bilayer
When considering a Li-intercalated hexagonal boron nitride bilayer (Li-hBN), the vertex corrections of electron–phonon interaction cannot be omitted. This is evidenced by the very high value of the ratio λω(D)/ε(F) ≈ 0.46, where λ is the electron–phonon coupling constant, ω(D) is the Debye frequency...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Beilstein-Institut
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7418097/ https://www.ncbi.nlm.nih.gov/pubmed/32821642 http://dx.doi.org/10.3762/bjnano.11.102 |
Sumario: | When considering a Li-intercalated hexagonal boron nitride bilayer (Li-hBN), the vertex corrections of electron–phonon interaction cannot be omitted. This is evidenced by the very high value of the ratio λω(D)/ε(F) ≈ 0.46, where λ is the electron–phonon coupling constant, ω(D) is the Debye frequency, and ε(F) represents the Fermi energy. Due to nonadiabatic effects, the phonon–induced superconducting state in Li-hBN is characterized by much lower values of the critical temperature (T(LOVC)(C) ∈ {19.1, 15.5, 11.8} K, for μ* ∈ {0.1, 0.14, 0.2}, respectively) than would result from calculations not taking this effect into account (T(ME)(C)∈ {31.9, 26.9, 21} K). From the technological point of view, the low value of T(C) limits the possible applications of Li-hBN. The calculations were carried out under the classic Migdal–Eliashberg formalism (ME) and the Eliashberg theory with lowest-order vertex corrections (LOVC). We show that the vertex corrections of higher order (λ(3)) lower the value of T(LOVC)(C) by a few percent. |
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