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Pomeranchuk and other Instabilities in the t-t' Hubbard model at the Van Hove Filling

V. Hankevych·I. Grote·F. Wegner
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Abstract

We present a stability analysis of the two-dimensional t-t' Hubbard model for various values of the next-nearest-neighbor hopping t', and electron concentrations close to the Van Hove filling by means of the flow equation method. For t' > -t/3 a d_{x^2-y^2}-wave Pomeranchuk instability dominates (apart from antiferromagnetism at small t'). At t' < -t/3 the leading instabilities are a g-wave Pomeranchuk instability and p-wave particle-hole instability in the triplet channel at temperatures T < 0.15t, and an s^*-magnetic phase for T > 0.15t; upon increasing the electron concentration the triplet analog of the flux phase occurs at low temperatures. Other weaker instabilities are found also.

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V. Hankevych, I. Grote, F. Wegner. 2002-05-10. Pomeranchuk and other Instabilities in the t-t' Hubbard model at the Van Hove Filling. https://doi.org/10.1103/physrevb.66.094516

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