Green function theory of dirty two-band superconductivity

Abstract

We study the effects of random nonmagnetic impurities on the superconducting transition temperature $T_c$ in a two-band superconductor, where we assume the 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 $T_c$ of the two states exactly in the same manner when the Hamiltonian preserves time-reversal symmetry. We find that a superconductor with larger hybridization shows more moderate suppression of $T_c$. 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.

11 pages, 2 figures

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Cited by in corpus (9)

• The Role of Odd-Frequency Pairing in Multiband Superconductors
• Van der Waals heterostructures with spin-orbit coupling
• Josephson effect in two-band superconductors
• General theory of robustness against disorder in multi-band superconductors
• Dirty two-band superconductivity with interband pairing order
• Odd-frequency superconductivity induced by non-magnetic impurities
• Superconductivity in Cu-doped Bi${}_2$Se${}_3$ with potential disorder
• Odd-frequency pairing in a superconductor coupled to two parallel nanowires
• Fulde-Ferrell-Larkin-Ovchinnikov state in a superconducting thin film attached to a ferromagnetic cluster