Inelastic neutron scattering on Ce pyrochlores: Signatures of electric monopoles

Abstract

We revisit the pyrochlore spin liquid materials Ce${}_2$Sn${}_2$O${}_7$ and Ce${}_2$Zr${}_2$O${}_7$ by examining the existing experiments. We continue to rely on the special properties of the dipole-octupole nature of the Ce${}^{3+}$ moment. The inelastic neutron scattering (INS) measurement in the octupolar U(1) spin liquid selects the (gapped) spinon continuum, and thus has suppressed spectral weights below the energy threshold of two spinon gaps. This measurement, however, includes all other emergent excitations at lower energies in the dipolar U(1) spin liquid, in particular, the gapless photon and the continuum of the electric monopoles. Although the electric monopole continuum is weakly gapped (compared to the larger spinon gap), the energy scale is actually close to the gauge photons, and the spectrum largely overlaps with the photons. Due to the background dual $\pi$ flux for the electric monopoles, the density of states is enhanced at lower energies, creating peak structures. This can be contrasted with the linearly suppressed spectral weight of the gauge photons at low energies. We propose that the electric monopole continuum should be mostly responsible for the low-energy spectrum in the INS measurement in the dipolar U(1) spin liquid. With these understanding and calculation, we discuss the available experimental results and predict further experiments for Ce${}_2$Sn${}_2$O${}_7$ and Ce${}_2$Zr${}_2$O${}_7$.

arXiv comment11 pages, 4 figures

References in corpus (36)

• Quantum Spin Liquids
• Pyrochlore Photons: The U(1) Spin Liquid in a S=1/2 Three-Dimensional Frustrated Magnet
• Quantum Excitations in Quantum Spin Ice
• Coulombic Quantum Liquids in Spin-1/2 Pyrochlores
• Dynamically-Induced Frustration as a Route to a Quantum Spin Ice State in Tb2Ti2O7 via Virtual Crystal Field Excitations and Quantum Many-Body Effects
• Seeing the light : experimental signatures of emergent electromagnetism in a quantum spin ice
• Frustrated quantum rare-earth pyrochlores
• Experimental signatures of a three-dimensional quantum spin liquid in effective spin-1/2 Ce2Zr2O7 pyrochlore
• Quantum spin ices and topological phases from dipolar-octupolar doublets on the pyrochlore lattice
• Quantum Spin Ice Dynamics in the Dipole-Octupole Pyrochlore Magnet Ce${}_2$Zr${}_2$O${}_7$
• Candidate Quantum Spin Liquid in the Ce\textsuperscript{3+} Pyrochlore Stannate Ce${}_2$Sn${}_2$O${}_7$
• A quantum liquid of magnetic octupoles on the pyrochlore lattice
• Symmetry Enriched U(1) Topological Orders for Dipole-Octupole Doublets on a Pyrochlore Lattice
• Noncollinear magnetism and spin-orbit coupling in 5d pyrochlore oxide Cd2Os2O7
• Time-reversal symmetric U(1) quantum spin liquids
• The case for a U(1)${}_{\pi }$ Quantum Spin Liquid Ground State in the Dipole-Octupole Pyrochlore Ce${}_2$Zr${}_2$O${}_7$
• Magnetic monopole condensation in pyrochlore ice quantum spin liquid: application to Pr2Ir2O7 and Yb2Ti2O7
• Sleuthing out exotic quantum spin liquidity in the pyrochlore magnet Ce${}_2$Zr${}_2$O${}_7$
• Nd2Sn2O7: an all-in-all-out pyrochlore magnet with no divergence-free field and anomalously slow paramagnetic spin dynamics
• Dirac's "magnetic monopole" in pyrochlore ice U(1) spin liquids: Spectrum and classification
• Pyrochlore U(1) spin liquid of mixed symmetry enrichments in magnetic fields
• Distinguishing dipolar and octupolar quantum spin ices using contrasting magnetostriction signatures
• Order out of a Coulomb phase and Higgs transtion: frustrated transverse interactions of Nd2Zr2O7
• Competing $U(1)$ and ${\mathbb{Z}}_2$ dipolar-octupolar quantum spin liquids on the pyrochlore lattice: application to Ce${}_2$Zr${}_2$O${}_7$
• Symmetry fractionalization in the gauge mean-field theory of quantum spin ice
• Dipolar spin ice regime proximate to an all-in-all-out Néel ground state in the dipolar-octupolar pyrochlore Ce${}_2$Sn${}_2$O${}_7$
• Anisotropic exchange Hamiltonian, magnetic phase diagram and domain inversion of Nd${}_2$Zr${}_2$O${}_7$
• Quantum Spin Ice Response to a Magnetic Field in the Dipole-Octupole Pyrochlore Ce${}_2$Zr${}_2$O${}_7$
• Spectroscopic signatures of fractionalization in octupolar quantum spin ice
• Topological thermal Hall effect of "magnetic monopoles" in pyrochlore U(1) spin liquid
• Extended Coulomb liquid of paired hardcore boson model on a pyrochlore lattice
• Spectroscopy of spinons in Coulomb quantum spin liquids
• $\mu$SR Study of the Dipole-Octupole Quantum Spin Ice Candidate Ce${}_2$Zr${}_2$O${}_7$
• Distinguishing thermodynamics and spectroscopy for octupolar U(1) spin liquid of Ce-pyrochlores
• Finite Temperature Dynamics in 0-Flux and $\pi$-Flux Quantum Spin Ice: Self-Consistent Exclusive Boson Approach
• Coulombic antiferromagnet in spin-1/2 pyrochlores with dipole-octupole doublets

Cited by in corpus (3)

• Influence of controlled disorder on the dipolar spin ice state of Ho-based pyrochlores
• Hearing the light: stray-field noise from the emergent photon in quantum spin ice
• Z${}_2$ topological orders in kagomé dipolar systems: Feedback from Rydberg quantum simulator