Publication Date:
2018-04-13
Description:
We study theoretically the effects of random nonmagnetic impurities on the superconducting transition temperature T c in a two-band superconductor characterized by an equal-time s -wave interband pairing order parameter. Because of the two-band degree of freedom, it is possible to define a spin-triplet s -wave pairing order parameter as well as a spin-singlet s -wave order parameter. The former belongs to odd-band-parity symmetry class, whereas the latter belongs to even-band-parity symmetry class. In a spin-singlet superconductor, T c is insensitive to the impurity concentration when we estimate the self-energy due to the random impurity potential within the Born approximation. On the other hand in a spin-triplet superconductor, T c decreases with the increase of the impurity concentration. We conclude that Cooper pairs belonging to odd-band-parity symmetry class are fragile under...
Electronic ISSN:
1367-2630
Topics:
Physics
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