Stability Analysis of the Hubbard-Model

2001/06/28 by I. Grote, Grote, I., E. Koerding +3
Physics and Astronomy · #FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con) #cond-mat.str-el #cond-mat.supr-con

paper · pdf · doi:10.48550/arxiv.cond-mat/0106604

25 pages, Latex2e, 4 figures and 1 table as ps-file, submission to Journal of Low Temperature Physics

arxiv created 2001/06/28 · arxiv updated 2009/11/30

Abstract

An effective Hartree-Fock-Bogoliubov-type interaction is calculated for the Hubbard-model in second order in the coupling by means of flow-equations. A stability analysis is performed in order to obtain the transition into various possible phases. We find, that the second order contribution weakens the tendency for the antiferromagnetic transition. Apart from a possible antiferromagnetic transition the d-wave Pomeranchuk instability recently reported by Halboth and Metzner is usually the strongest instability. A newly found instability is of p-wave character and yields a band-splitting. In the BCS-channel one obtains the strongest contribution for d_x²-y²-waves. Other types of instabilities of comparable strength are also reported.

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