Green's-function theory of dirty two-band superconductivity

Yasuhiro Asano, Alexander A. Golubov

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2 Citations (Scopus)
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Abstract

We study the effects of random nonmagnetic impurities on the superconducting transition temperature Tc in a two-band superconductor, where we assume an equal-time spin-singlet s-wave pair potential in each conduction band and the hybridization between the two bands as well as the band asymmetry. In the clean limit, the phase of hybridization determines the stability of two states, called s++ and s+-. The interband impurity scatterings decrease Tc of the two states exactly in the same manner when time-reversal symmetry is preserved in the Hamiltonian. We find that a superconductor with larger hybridization shows more moderate suppression of Tc. This effect can be explained by the presence of odd-frequency Cooper pairs, which are generated by the band hybridization in the clean limit and are broken by impurities.

Original languageEnglish
Article number214508
JournalPhysical review B: Covering condensed matter and materials physics
Volume97
Issue number21
DOIs
Publication statusPublished - 12 Jun 2018

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Superconductivity
Green's function
Green's functions
superconductivity
Impurities
Superconducting materials
impurities
Hamiltonians
Conduction bands
Superconducting transition temperature
Scattering
conduction bands
transition temperature
asymmetry
retarding
symmetry
scattering

Cite this

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Green's-function theory of dirty two-band superconductivity. / Asano, Yasuhiro; Golubov, Alexander A.

In: Physical review B: Covering condensed matter and materials physics, Vol. 97, No. 21, 214508, 12.06.2018.

Research output: Contribution to journalArticleAcademicpeer-review

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