Abstract
The energy gap and the transition temperature of the weak coupling superconductors tin and indium are measured as a function of the mean free path of the electrons. Both of them increase with decreasing mean free path. The ratioα=2Δ 0/kTc increases proportionally to the reciprocal mean free path from 3.6 to 4.0 for tin and from 3.6 to 3.95 for indium. A theoretical consideration is presented showing that the electron-electron interaction is increased in dirty superconductors. Without any fit we find from the theoretical calculation an increase inNV for indium ofδNV=5 · 10−10 m/l tr and for tinδNV=2 · 10−10 m/l tr (ltr is the transport mean free path of the electrons). The experiments give an increase inNV for indium ofδNV=4.2 · 10−10 m/ltr and for tinδNV=1.7 · 10−10 m/l tr. The agreement is surprisingly good.
Similar content being viewed by others
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Bergmann, G. Energy gap, transition temperature and electron-electron interaction of the weak coupling superconductors tin and indium as a function of the mean free path of the electrons. Z. Physik 228, 25–40 (1969). https://doi.org/10.1007/BF01392431
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF01392431