Role of vertex corrections in the spin-fluctuation mediated pairing mechanism

Abstract

We study numerically and partly diagrammatically the renormalization of the electron-spin interaction or vertex in a two-dimensional one-band Hubbard model with spin-fluctuation momentum transfer ${\vv q}=(π,π)$. We find that the renormalized electron-spin vertex decreases quite generally with decreasing temperature at all doping densities. As a combination of two concurring effects, i.e. the decrease of the vertex and the increase of the spin susceptibility, the effective pairing interaction increases with lowering temperature in the intermediate-correlation regime, but {\it flattens off} in the strong-correlation regime. Our findings indicate that in the high-T${}_c$ cuprates the pairing mediated by antiferromagnetic spin fluctuations is substantially reduced due to vertex corrections.

arXiv commentFinal version, accepted for publication in Europhysics Letters

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Cited by in corpus (4)

• Explaining the pseudogap through damping and antidamping on the Fermi surface by imaginary spin scattering
• The superconducting gap in the Hubbard model and the two gap energy scales in high-Tc cuprates
• Renormalization of the electron-spin-fluctuation interaction in the t-t'-U Hubbard model
• Pairing boost from enhanced spin-fermion coupling in the pseudogap regime