Effects of impurity vertex correction on the NMR coherence peak in {ital s}-wave superconductors
- Department of Physics, Sung Kyun Kwan University, Suwon 440-746 (Korea, Republic of)
- Department of Physics, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)
We study the effects of nonmagnetic impurity vertex correction on nuclear spin-lattice relaxation rate 1/{ital T}{sub 1} of conventional {ital s}-wave superconductors within the Eliashberg formalism. We obtain, with a self-consistent {ital t}-matrix treatment of impurity scatterings, the expression for impurity vertex function and nuclear spin-lattice relaxation rate. The 1/{ital T}{sub 1} is evaluated with a simple approximation on angular average, and found to agree in clean limit with the previous result that 1/({ital T}{sub 1}{ital T}) remains unrenormalized under the impurity vertex correction. As dirtiness is increased, on the other hand, the coherence peak in 1/({ital T}{sub 1}{ital T}) is found to increase due to the impurity vertex correction. This result is discussed in connection with the experimental observations on conventional superconductors.
- OSTI ID:
- 115864
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 52, Issue 10; Other Information: PBD: 1 Sep 1995
- Country of Publication:
- United States
- Language:
- English
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