Symmetry breaking via Kondo hybridization: Chiral nematic metal in Pr2Ir2O7

TL;DR

This paper introduces a new mechanism where Kondo hybridization between localized spins and conduction electrons in Pr2Ir2O7 leads to symmetry breaking, resulting in anomalous Hall effects and other orderings without magnetic order.

Contribution

It proposes a novel symmetry-breaking mechanism via Kondo hybridization in frustrated magnets, explaining anomalous Hall effects in Pr2Ir2O7 without magnetic order.

Findings

Kondo hybridization breaks spatial and time-reversal symmetries.

Results in anomalous Hall conductivity.

Predicts small magnetic, quadrupolar, and charge orderings.

Abstract

In frustrated magnets when magnetic ordering is suppressed down to low temperature, the formation of a quantum spin liquid becomes a possibility. How such a spin liquid manifests in the presence of conduction electrons is a question with potentially rich physical consequences, particularly when both the localized spins and conduction electrons reside on frustrated lattices. We propose a novel mechanism for symmetry breaking in systems where conduction electrons hybridize with a quantum spin liquid through Kondo couplings. We apply this to the pyrochlore iridate Pr2Ir2O7, which exhibits an anomalous Hall effect without clear indications of magnetic order. We show that Kondo hybridization between the localized Pr pseudo-spins and Ir conduction electrons breaks some of the spatial symmetries, in addition to time-reversal regardless of the form ofthe coupling. These broken symmetries result in an anomalous Hall conductivity and induce small magnetic, quadrupolar and charge orderings. Further experimental signatures are proposed.