Alternative Kondo breakdown mechanism: Orbital-selective orthogonal metal transition

TL;DR

This paper introduces an orbital-selective orthogonal metal transition in the extended Anderson lattice model, revealing a new Kondo breakdown mechanism dominated by a z=3 critical mode, with implications for heavy fermion quantum criticality.

Contribution

It extends the orthogonal metal concept to the Anderson lattice model, proposing an alternative Kondo breakdown mechanism involving orbital selectivity and a z=3 critical mode.

Findings

Disordered state is an orbital-selective orthogonal metal.

Critical behavior is dominated by a z=3 mode.

Provides a new perspective on Kondo breakdown in heavy fermion systems.

Abstract

In a recent paper of Nandkishore and Senthil [arxiv:1201.5998 (2012)], a concept of orthogonal metal has been introduced to reinterpret the disordered state of slave-spin representation in the Hubbard model as an exotic gapped metallic state. We extend this concept to study the corresponding quantum phase transition in the extended Anderson lattice model. It is found that the disordered state of slave spins in this model is an orbital-selective orthogonal metal, a generalization of the concept of the orthogonal metal in the Hubbard model. Near the quantum critical point the essential behaviors are dominated by a z = 3 critical mode, which is in contrast to the naive expectation in the Hubbard model. The result provides alternative Kondo breakdown mechanism for heavy fermion compounds underlying the physics of the orbital-selective orthogonal metal in the disordered state, which is different from the conventional Kondo breakdown mechanism with the fractionalized Fermi liquid picture. This work is expected to be useful in understanding the quantum criticality happening in some heavy fermion materials and other related strongly correlated systems.