Exact ground-state for the periodic Anderson model in D=2 dimensions at finite value of the interaction and absence of the direct hopping in the correlated f-band

TL;DR

This paper presents the first exact ground-state solutions for the two-dimensional periodic Anderson model at finite interaction strength without direct f-electron hopping, revealing a non-Fermi liquid itinerant phase.

Contribution

The authors develop a generalized block operator technique to derive exact ground-states for the 2D periodic Anderson model with finite U and no direct f-electron hopping.

Findings

Identified a non-Fermi liquid itinerant phase at finite U

Exact ground-states obtained without requiring anisotropic unit cells

The method extends plaquette operator approach to larger blocks

Abstract

We report for the first time exact ground-states deduced for the D=2 dimensional generic periodic Anderson model at finite $U$, the Hamiltonian of the model not containing direct hopping terms for $f$-electrons $(t^f = 0)$. The deduced itinerant phase presents non-Fermi liquid properties in the normal phase, emerges for real hybridization matrix elements, and not requires anisotropic unit cell. In order to deduce these results, the plaquette operator procedure has been generalised to a block operator technique which uses blocks higher than an unit cell and contains $f$-operator contributions acting only on a single central site of the block.