Superconducting order parameters with sign changes: The density of states and impurity scattering
- Department of Physics, Purdue University, West Lafayette, Indiana 47907 (United States)
We compute {ital N}{sub {ital s}}({ital E}) for a family of superconducting order parameters with sign changes at the Fermi surface, and find surprising results. We consider all {Delta}({bold {cflx k}}) such that {Delta}({bold {cflx k}})=+{Delta}{sub 0} on part of the Fermi surface, and {Delta}({bold {cflx k}})={minus}{Delta}{sub 0} on the rest, yielding an average of {l_angle}{Delta}({bold {cflx k}}){r_angle}={ital r}{Delta}{sub 0}, where 0{le}{ital r}{le}1. For 0{lt}{ital r}{lt}1, as the impurity concentration increases, the number of low-lying states increases, and the superconductor becomes gapless. As the impurity concentration is further increased, the gap in the spectrum is restored, and {ital N}{sub {ital s}}({ital E}) approaches the pure limit BCS form, with a renormalized gap. {copyright} {ital 1996 The American Physical Society.}
- Research Organization:
- Purdue Research Foundation
- DOE Contract Number:
- FG02-90ER45427
- OSTI ID:
- 286679
- Journal Information:
- Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 5 Vol. 54; ISSN PRBMDO; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
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