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Anisotropic Superconductivity in Highly Disordered Systems
| Title: | Anisotropic Superconductivity in Highly Disordered Systems |
| Authors: | Toyama, Takahiro Browse this author | | Ohkawa, Fusayoshi J. Browse this author →KAKEN DB |
| Keywords: | anisotropic superconductivity | | disorder | | AG theory | | cuprate oxide |
| Issue Date: | 15-Sep-2009 |
| Publisher: | Physical Society of Japan |
| Journal Title: | Journal of the Physical Society of Japan |
| Volume: | 78 |
| Issue: | 9 |
| Start Page: | 094712 |
| Publisher DOI: | 10.1143/JPSJ.78.094712 |
| Abstract: | The gap equation for anisotropic superconductivity is solved in the presence of elastic scatterings by nonmagnetic and magnetic impurities, which are treated by the self-consistent Born approximation, and inelastic scatterings, which are phenomenologically treated. When elastic scatterings are strong, even at T = 0 K, coherence peaks almost disappear and the gap is a pseudogap, i.e., the density of states ρ(ε) is nonzero at the chemical potential, which means that the T-linear specific heat coefficient is nonzero in the superconducting state. At T = 0 K in such a case, the low-energy part of ρ(ε) or the gap spectrum has a concave-cap V shape, which is in contrast to a convex-cup V shape in the absence of scattering. When elastic or inelastic scatterings are strong, the ratio εG(0)/kBTc is much larger than its mean-field value of about 4, where εG(0) is the gap at T = 0 K and Tc is the superconducting critical temperature. The large εG(0)/kBTc ≃ 8 and the linear decrease in Tc in residual resistivity, both of which are observed in cuprate superconductors and the latter of which is inconsistent with the Abrikosov and Gor'kov theory, can be explained by the temperature-dependent pair breaking estimated from the T-linear coefficient of resistivity, which is about 1 μΩcm/K. |
| Rights: | © 2009 The Physical Society of Japan |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/39309 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 大川 房義
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