Mutual information, quantum phase transition, and phase coherence in Kondo systems

We propose a static auxiliary field approximation to study the hybridization physics of Kondo systems without sign problem and use mutual information measure intersite correlations. Our method takes full account spatial fluctuations fields at all orders overcomes artificial (first-order) phase transition predicted in mean-field approximation. When applied two-impurity model, it reveals logarithmically divergent amplitude near so-called "Varma-Jones" fixed point large manifesting development coherence regime, with observable influences on physical properties. These highlight importance confirm as useful tool explore systems.