Hidden phases born of a quantum spin liquid: Application to pyrochlore spin ice

TL;DR

This paper introduces a formalism to explore hidden and exotic phases emerging from quantum spin liquids, specifically in pyrochlore spin ice, revealing new phases like $ ext{Z}_2$ QSLs and supersolids without fine-tuning.

Contribution

The authors develop a novel approach to identify and analyze hidden phases arising from interactions in quantum spin liquids, expanding the understanding of phase diversity in pyrochlore spin ice.

Findings

Discovery of a $ ext{Z}_2$ QSL phase from a U(1) QSL

Identification of a supersolid phase in the phase diagram

Support from numerical simulations validating the theoretical framework

Abstract

Quantum spin liquids (QSL) have generated considerable excitement as phases of matter with emergent gauge structures and fractionalized excitations. In this context, phase transitions out of QSLs have been widely discussed as Higgs transitions from deconfined to confined phases of a lattice gauge theory. However the possibility of a wider range of novel phases, occuring between these two limits, has yet to be systematically explored. In this Letter, we develop a formalism which allows for interactions between fractionalised quasiparticles coming from the constraint on the physical Hilbert space, and can be used to search for exotic, hidden phases. Taking pyrochlore spin ice as a starting point, we show how a U(1) QSL can give birth to abundant daughter phases, without need for fine--tuning of parameters. These include a (charged--) $\mathbb{Z}_2$ QSL, and a supersolid. We discuss implications for experiment, and numerical results which support our analysis. These results are of broad relevance to QSL subject to a parton description, and offer a new perspective for searching exotic hidden phases in quantum magnets.