Interplay of Correlations and Kohn Anomalies in Three Dimensions: Quantum Criticality with a Twist

Phys Rev Lett. 2017 Jul 28;119(4):046402. doi: 10.1103/PhysRevLett.119.046402. Epub 2017 Jul 26.

Abstract

A general understanding of quantum phase transitions in strongly correlated materials is still lacking. By exploiting a cutting-edge quantum many-body approach, the dynamical vertex approximation, we make important progress, determining the quantum critical properties of the antiferromagnetic transition in the fundamental model for correlated electrons, the Hubbard model in three dimensions. In particular, we demonstrate that-in contradiction to the conventional Hertz-Millis-Moriya theory-its quantum critical behavior is driven by the Kohn anomalies of the Fermi surface, even when electronic correlations become strong.