O ct 1 99 6 Vertex corrections in antiferromagnetic spin fluctuation theories
نویسندگان
چکیده
We calculate the first vertex correction δΛ k to the bare vertex Λ • in the nearly antiferromagnetic spin fluctuation Fermi liquid theory of the cuprate superconductor YBa 2 Cu 3 O 7. It is calculated for k on the Fermi surface, and Q = (± π a , ± π a). We find that the dimensionless ratio |δΛ k |/Λ • , which parametrizes the vertex correction, is not small. It is a maximum for k = k h , where k h is a " hot spot " on the Fermi surface. This makes large quantitative corrections to the theory.
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