Correlation functions for composite operators in the Hubbard model

2001/07/18 by Tobias Baier, Baier, Tobias, Eike Bick +4
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #High Energy Physics - Theory (hep-th) #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con) #cond-mat.str-el #cond-mat.supr-con #hep-th

paper · pdf · doi:10.48550/arxiv.cond-mat/0107390

29 pages, 5 figures

arxiv created 2001/07/18 · openalex publication_date 2001/07/18 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We compute the correlation functions for antiferromagnetic and d-wave superconducting fermion bilinears in a generalized mean field type approximation for the Hubbard model. For high temperature our explicit expressions show that homogeneous field configurations are preferred for these composite bosons. Below a critical temperature we find spontaneous symmetry breaking with homogeneous expectation values of the composite fields. Our results can be used to device a nonperturbative flow equation for the exploration of the low temperature regime.

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