Efficient Fermionic One-Loop RG for the 2D Hubbard Model at Van Hove Filling

Christoph Husemann; Manfred Salmhofer

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arXiv · 0902.1651

Efficient Fermionic One-Loop RG for the 2D Hubbard Model at Van Hove Filling

Christoph Husemann·Manfred Salmhofer

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Abstract

We propose a novel parametrization of the four-point vertex function in the one-loop one-particle irreducible renormalization group (RG) scheme for fermions. It is based on a decomposition of the effective two-fermion interaction into fermion bilinears that interact via exchange bosons. Besides being more efficient than previous N-patch schemes, this parametrization also reduces the ambiguity of introducing boson fields. We apply this parametrization to the two-dimensional (t,t')-Hubbard model using a novel $Ω$-frequency regularization.

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Christoph Husemann, Manfred Salmhofer. 2009-02-10. Efficient Fermionic One-Loop RG for the 2D Hubbard Model at Van Hove Filling. https://arxiv.org/abs/0902.1651

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