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Phase-diagram and quasiparticles of a lattice SU(2) scalar-fermion model in (2+1) dimensions

J. L. Alonso·Ph. Boucaud·V. Martin-Mayor·A. J. van der Sijs
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Abstract

The phase diagram at zero temperature of a lattice SU(2) scalar-fermion model in (2+1) dimensions is studied numerically and with Mean-Field methods. Special attention is devoted to the strong coupling regime. We have developed a new method to adaptate the Hybrid Monte Carlo algorithm to the O(3) non-linear $σ$ model constraint. The charged excitations in the various phases are studied at the Mean-Field lev el. Bound states of two charged fermions are found in a strongly coupled {\it paramagnetic} phase. On the other hand, in the strongly coupled antiferromagnetic phase fermionic excitations around momenta $(\pm\fracπ{2},\pm\fracπ{2},\pm\fracπ{2})$ emerge.

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J. L. Alonso, Ph. Boucaud, V. Martin-Mayor, A. J. van der Sijs. 1999-07-20. Phase-diagram and quasiparticles of a lattice SU(2) scalar-fermion model in (2+1) dimensions. https://doi.org/10.1103/physrevd.61.034501

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