Chiral RKKY interaction in Pr[subscript 2]Ir[subscript 2]O[subscript 7]

Abstract

Motivated by the potential chiral spin liquid in the metallic spin ice Pr[subscript 2]Ir[subscript 2]O[subscript 7], we consider how such a chiral state might be selected from the spin-ice manifold. We propose that chiral fluctuations of the conducting Ir moments promote ferrochiral couplings between the local Pr moments, as a chiral analog of the magnetic RKKY effect. Pr[subscript 2]Ir[subscript 2]O[subscript 7] provides an ideal setting to explore such a chiral RKKY effect, given the inherent chirality of the spin-ice manifold. We use a slave-rotor calculation on the pyrochlore lattice to estimate the sign and magnitude of the chiral coupling, and find it can easily explain the 1.5 K transition to a ferrochiral state.