In the present work we calculate for the first time the density of states of MgB2 for different tunneling directions by directly solving the two-band Eliashberg equations in the real-axis formulation starting from the first-principle calculation of the interband and intraband electron-phonon spectral functions. This complicated numeric procedure allows preserving the fine structures of the DOS in the phonon energy range. We show that the numeric inversion of the standard single-band Eliashberg equations when applied to the densities of states obtained by the two-band model may lead to artifacts in the extracted electron-phonon spectral function α2F(ω). We also suggest that the small DOS structures produced by the two-band interaction at energies between 20 and 100 meV can be observed only at very low temperature in junctions in perfect clean limit.

Electron-phonon spectral function and two-band model in tunneling measurements on MgB2 / Ummarino, G. A.; Gonnelli, R. S.; Dolgov, O. V.; Shulga, S. V.. - In: INTERNATIONAL JOURNAL OF MODERN PHYSICS B. - ISSN 0217-9792. - ELETTRONICO. - 17:4-6 I(2003), pp. 643-648. [10.1142/s0217979203016364]

Electron-phonon spectral function and two-band model in tunneling measurements on MgB2

Ummarino G. A.;Gonnelli R. S.;
2003

Abstract

In the present work we calculate for the first time the density of states of MgB2 for different tunneling directions by directly solving the two-band Eliashberg equations in the real-axis formulation starting from the first-principle calculation of the interband and intraband electron-phonon spectral functions. This complicated numeric procedure allows preserving the fine structures of the DOS in the phonon energy range. We show that the numeric inversion of the standard single-band Eliashberg equations when applied to the densities of states obtained by the two-band model may lead to artifacts in the extracted electron-phonon spectral function α2F(ω). We also suggest that the small DOS structures produced by the two-band interaction at energies between 20 and 100 meV can be observed only at very low temperature in junctions in perfect clean limit.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11583/2878621