Sleuthing out exotic quantum spin liquidity in the pyrochlore magnet Ce${}_2$Zr${}_2$O${}_7$

Abstract

The search for quantum spin liquids (QSL) -- topological magnets with fractionalized excitations -- has been a central theme in condensed matter and materials physics. While theories are no longer in short supply, tracking down materials has turned out to be remarkably tricky, in large part because of the difficulty to diagnose experimentally a state with only topological, rather than conventional, forms of order. Pyrochlore systems have proven particularly promising, hosting a classical Coulomb phase in the spin ices Dy/Ho${}_2$Ti${}_2$O${}_7$, with subsequent proposals of candidate QSLs in other pyrochlores. Connecting experiment with detailed theory exhibiting a robust QSL has remained a central challenge. Here, focusing on the strongly spin-orbit coupled effective $S=1/2$ pyrochlore Ce${}_2$Zr${}_2$O${}_7$, we analyse recent thermodynamic and neutron scattering experiments, to identify a microscopic effective Hamiltonian through a combination of finite temperature Lanczos, Monte Carlo and analytical spin dynamics calculations. Its parameter values suggest a previously unobserved exotic phase, a $\pi$-flux U(1) QSL. Intriguingly, the octupolar nature of the moments makes them less prone to be affected by crystal imperfections or magnetic impurities, while also hiding some otherwise characteristic signatures from neutrons, making this QSL arguably more stable than its more conventional counterparts.

7 pages, 4 figures. Supplementary material consists of 8+ pages, 6 figures and 1 table

References in corpus (8)

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• Dirac Strings and Magnetic Monopoles in Spin Ice Dy2Ti2O7
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• Is the Yb2Ti2O7 pyrochlore a quantum spin ice?
• Symmetry Enriched U(1) Topological Orders for Dipole-Octupole Doublets on a Pyrochlore Lattice
• Spin Dynamics in Pyrochlore Heisenberg Antiferromagnets
• Comprehensive study of the dynamics of a classical Kitaev spin liquid
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Cited by in corpus (39)

• Thermal Hall effects in quantum magnets
• Experimental signatures of quantum and topological states in frustrated magnetism
• Kitaev Quantum Spin Liquids
• Magnetic field effects in an octupolar quantum spin liquid candidate
• Uncovering footprints of dipolar-octupolar quantum spin ice from neutron scattering signatures
• 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${}_7$
• Quantum Spin Ice Response to a Magnetic Field in the Dipole-Octupole Pyrochlore Ce${}_2$Zr${}_2$O${}_7$
• Probing octupolar hidden order via Janus impurities
• Thermal spin dynamics of Kitaev magnets $-$ scattering continua and magnetic field induced phases within a stochastic semiclassical approach
• Possible realization of three-dimensional quantum spin liquid behavior in HoVO4
• $\mu$SR Study of the Dipole-Octupole Quantum Spin Ice Candidate Ce${}_2$Zr${}_2$O${}_7$
• Quantum spin liquids on the diamond lattice
• Emergent photons and fractionalized excitations in a quantum spin liquid
• Distinguishing thermodynamics and spectroscopy for octupolar U(1) spin liquid of Ce-pyrochlores
• A pseudofermion functional renormalization group study of dipolar-octupolar pyrochlore magnets
• Ultrasound detection of emergent photons in generic quantum spin ice
• Finite Temperature Dynamics in 0-Flux and $\pi$-Flux Quantum Spin Ice: Self-Consistent Exclusive Boson Approach
• Linear scaling relationship of Néel temperature and dominant magnons in pyrochlore ruthenates
• Exploiting polarization dependence in two dimensional coherent spectroscopy: examples of Ce${}_2$Zr${}_2$O${}_7$ and Nd${}_2$Zr${}_2$O${}_7$
• Dipolar-octupolar correlations and hierarchy of exchange interactions in Ce${}_2$Hf${}_2$O${}_7$
• Spin ice in a general applied magnetic field: Kasteleyn transition, magnetic torque and rotational magnetocaloric effect
• Two-Peak Heat Capacity Accounts for $R\ln (2)$ Entropy and Ground State Access in the Dipole-Octupole Pyrochlore Ce${}_2$Hf${}_2$O${}_7$
• Thermodynamics of the dipole-octupole pyrochlore magnet Ce${}_2$Hf${}_2$O${}_7$ in applied magnetic fields
• Order, Disorder and Monopole Confinement in the Spin-$1/2$ XXZ Model on a Pyrochlore Tube
• Single Crystal Diffuse Neutron Scattering Study of the Dipole-Octupole Quantum Spin Ice Candidate Ce${}_2$Zr${}_2$O${}_7$: No Apparent Octupolar Correlations Above $T=0.05$ K
• Classical spin models of the windmill lattice and their relevance for PbCuTe${}_2$O${}_6$
• Inelastic neutron scattering on Ce pyrochlores: Signatures of electric monopoles
• Magnetic Field Response of Dipolar-Octupolar Quantum Spin Ice
• Coulombic antiferromagnet in spin-1/2 pyrochlores with dipole-octupole doublets
• Competition between $d$-wave and $d$+$is$-wave superconductivity in the Hubbard model on a checkerboard lattice
• Possibility of ferro-octupolar order in Ba${}_2$CaOsO${}_6$ assessed by X-ray magnetic dichroism measurements
• Quantum entanglement of XY-type spin dimers in Shastry-Sutherland lattice
• Influence of controlled disorder on the dipolar spin ice state of Ho-based pyrochlores
• Classification and correlation signatures of chiral spin liquids on the pyrochlore lattice
• Hearing the light: stray-field noise from the emergent photon in quantum spin ice
• Towards a global phase diagram of Ce-based dipolar-octupolar pyrochlore magnets under magnetic fields
• Emergent Chiral Metal near a Kondo Breakdown Quantum Phase Transition
• Disorder-induced proximate quantum spin ice phase in Pr2Sn2O7