Symmetry Enriched U(1) Topological Orders for Dipole-Octupole Doublets on a Pyrochlore Lattice

TL;DR

This paper investigates symmetry enriched U(1) quantum spin liquids on the pyrochlore lattice, focusing on the novel octupolar U(1) QSL and its experimental signatures in candidate materials like Ce$_2$Sn$_2$O$_7$.

Contribution

It introduces and characterizes the octupolar U(1) QSL, a novel phase supported by dipole-octupole doublets, and predicts its unique physical and spectroscopic properties.

Findings

Identification of two distinct U(1) QSL ground states: dipolar and octupolar.

Prediction of unique spectroscopic signatures of the octupolar U(1) QSL.

Proposal of an Anderson-Higgs transition driven by magnetic fields.

Abstract

Symmetry plays a fundamental role in our understanding of both conventional symmetry breaking phases and the more exotic quantum and topological phases of matter. We explore the experimental signatures of symmetry enriched U(1) quantum spin liquids (QSLs) on the pyrochlore lattice. We point out that the Ce local moment of the newly discovered pyrochlore QSL candidate Ce$_2$Sn$_2$O$_7$, is a dipole-octupole doublet. The generic model for these unusual doublets supports two distinct symmetry enriched U(1) QSL ground states in the corresponding quantum spin ice regimes. These two U(1) QSLs are dubbed dipolar U(1) QSL and octupolar U(1) QSL. While the dipolar U(1) QSL has been discussed in many contexts, the octupolar U(1) QSL is rather unique. Based on the symmetry properties of the dipole-octupole doublets, we predict the peculiar physical properties of the octupolar U(1) QSL, elucidating the unique spectroscopic properties in the externalmagnetic fields. We further predict the Anderson-Higgs transition from the octupolar U(1) QSL driven by the external magnetic fields. We identify the experimental relevance with the candidate material Ce$_2$Sn$_2$O$_7$ and other dipole-octupole doublet systems.