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Exact solutions for the periodic Anderson model in 2D: A Non-Fermi liquid state in normal phase

Peter Gurin·Zsolt Gulacsi
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Abstract

Presenting exact solutions for the two dimensional periodic Anderson model with finite and nonzero on-site interaction U>0, we are describing a rigorous non-Fermi liquid phase in normal phase and 2D. This new state emerges in multi-band interacting Fermi systems above half filling, being generated by a flat band effect. The momentum distribution function n_k together with its derivatives of any order is continuous. The state possesses a well defined Fermi energy, but the Fermi momentum concept is not definable, so the Fermi surface in k-space is missing. The state emerges in the vicinity of a Mott insulating phase when lattice distortions are present, is highly degenerated and paramagnetic. A gap is present at high U in the density of low lying excitations. During low lying excitations, quasi-particles are not created above the Fermi level, only the number of particles at the Fermi energy increases.

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Peter Gurin, Zsolt Gulacsi. 2001-04-11. Exact solutions for the periodic Anderson model in 2D: A Non-Fermi liquid state in normal phase. https://doi.org/10.1103/physrevb.64.045118

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