2002/08/01 by Yoji Ohashi · 1 citation
Materials Science · Physics and Astronomy · #Born approximation #Bound state #Excitation #Impurity #Ionized impurity scattering #Iron-based superconductors research #Mixing (physics) #Physics of Superconductivity and Magnetism #Rare-earth and actinide compounds #Scattering #Superconductivity #cond-mat.supr-con
paper · pdf · doi:10.1143/jpsj.71.1978
published as J. Phys. Soc. Jpn. 71 (2002) 1978 · 28pages, 10 figures
openalex publication_date 2002/08/01 · arxiv created 2003/04/22 · arxiv updated 2015/06/24 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We investigate nonmagnetic impurity effects in two-band superconductors, focusing on the effects of interband scatterings. Within the Born approximation, it is known that interband scatterings mix order parameters in the two bands. In particular, only one averaged energy gap appears in the excitation spectrum in the dirty limit. [G. Gusman: J. Phys. Chem. Solids \bf 28 (1967) 2327.] In this paper, we take into account the interband scattering within the t-matrix approximation beyond the Born approximation in the previous work. We show that, although the interband scattering is responsible for the mixing effect, this effect becomes weak when the interband scattering becomes very strong. In the strong interband scattering limit, a two-gap structure corresponding to two order parameters recovers in the superconducting density of states. We also show that a bound state appears around a nonmagnetic impurity depending on the phase of interband scattering potential.