Half moons are pinch points with dispersion

Abstract

"Pinch points," singular features observed in (quasi-)elastic neutron scattering, are a widely discussed hallmark of spin liquids with an emergent gauge symmetry. Much less attention has been paid to "half moons," distinctive crescent patterns at finite energy, which have been observed in experiments on a number of pyrochlore magnets, and in a wide range of model calculations. Here we unify these two phenomena within a single framework, paying particular attention to the case of ordered, or field-saturated states, where pinch points and half moons can be found in bands of excitations above a gap. We find that half moons are nothing other than pinch points inscribed on a dispersing band. Molecular dynamics simulations of the kagome lattice antiferromagnet are used to explore how these bands evolve into the ground state and excitations of a classical spin liquid. We explicitly demonstrate that this theory can reproduce the pinch points and half moons observed in Nd${}_2$Zr${}_2$O${}_7$.

arXiv comment6 pages, 4 figures. Supplementary material: 10 pages, 3 figures

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Cited by in corpus (24)

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• Fragmentation in Frustrated Magnets -- A review
• Pinch-points to half-moons and up in the stars: the kagome skymap
• Magnetic clustering, half-moons, and shadow pinch points as signals of a proximate Coulomb phase in frustrated Heisenberg magnets
• Theory of Ca${}_{10}$Cr${}_7$O${}_{28}$ as a bilayer breathing-kagome magnet: Classical thermodynamics and semi-classical dynamics
• How many spin liquids are there in Ca${}_{10}$Cr${}_7$O${}_{28}$?
• Combined approach to analyze and classify families of classical spin liquids
• Thermodynamics of the pyrochlore-lattice quantum Heisenberg antiferromagnet
• Skyrmion fluid and bimeron glass protected by a chiral spin liquid on a kagome lattice
• Spin dynamics and unconventional Coulomb phase in Nd${}_2$Zr${}_2$O${}_7$
• Anisotropic exchange Hamiltonian, magnetic phase diagram and domain inversion of Nd${}_2$Zr${}_2$O${}_7$
• Arc-shaped structure factor in the $J_1$-$J_2$-$J_3$ classical Heisenberg model on the triangular lattice
• Rod motifs in neutron scattering in spin ice
• From chiral spin liquids to skyrmion fluids and crystals, and their interplay with itinerant electrons
• Spin dynamics of the antiferromagnetic Heisenberg model on a kagome bilayer
• Screening and the Pinch Point Paradox in Spin Ice
• Trimer classical spin liquid from interacting fractional charges
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• Pinch points and half-moons in dipolar-octupolar Nd${}_2$Hf${}_2$O${}_7$
• Dynamic Spin-Lattice Coupling and Statistical Interpretation for the Molecular-Like Excitations in Frustrated Pyrochlores
• Pinch-point spectral singularity from the interference of topological loop states
• Pinch points and half moons encode Berry curvature
• Spinor ice correlation in flat-band electronic states on kagome and pyrochlore lattices with spin-orbit coupling
• Dynamical spin correlations in kagome antiferromagnets: comparison of Abrikosov fermion and Schwinger boson approaches beyond mean field