A field trip through spin ice

Abstract

Fractionalisation -- the breaking up of an apparently indivisible microscopic degree of freedom -- is one of the most counterintuitive phenomena in many-body physics. Here we study its most fundamental manifestation in spin ice, the only known fractionalised magnetic compound in 3D: we directly visualise the $1/r^2$ magnetic Coulomb field of monopoles which emerge as the atomic magnetic dipoles fractionalise. We analyse the internal magnetic field distribution, relevant for local experimental probes. In particular, we present new zero-field NMR measurements which exhibit excellent agreement with the calculated lineshapes, noting that this experimental technique can in principle measure directly the monopole density in spin ice. The distribution of field strengths is captured by a simple analytical form which exhibits a low density of low-field sites---in apparent disagreement with reported $\mu$SR results. Counterintuitively, the density of low-field locations decreases as the local ferromagnetic correlations imposed by the ice rules weaken.

(7 pages; 6 figures; v2 revised version for publication)

References in corpus (7)

• Artificial "spin ice" in a geometrically frustrated lattice of nanoscale ferromagnetic islands
• Dirac Strings and Magnetic Monopoles in Spin Ice Dy2Ti2O7
• Spin Ice, Fractionalization and Topological Order
• Low Temperature Spin Freezing in Dy2Ti2O7 Spin Ice
• Observation of Magnetic Monopoles in Spin Ice
• Spin Ice: Magnetic Excitations without Monopole Signatures using Muon Spin Rotation
• Monopoles, magnetricity and the stray field from spin ice

Cited by in corpus (16)

• Quantum Spin Ice: A Search for Gapless Quantum Spin Liquids in Pyrochlore Magnets
• Magnetic-Moment Fragmentation and Monopole Crystallization
• Experimental signatures of quantum and topological states in frustrated magnetism
• Single-ion anisotropy and magnetic field response in spin ice materials Ho${}_2$Ti${}_2$O${}_7$ and Dy${}_2$Ti${}_2$O${}_7$
• New physics in frustrated magnets: Spin ices, monopoles, etc
• Fragmentation in Frustrated Magnets -- A review
• Correlated Quantum Tunnelling of Monopoles in Spin Ice
• Tunable non-equilibrium dynamics: field quenches in spin ice
• AC Wien effect in spin ice, manifest in non-linear non-equilibrium susceptibility
• Generalised Longitudinal Susceptibility for Magnetic Monopoles in Spin Ice
• Monopole holes in a partially ordered spin liquid
• Dipolar spin ice states with fast monopole hopping rate in CdEr${}_2$X${}_4$ (X = Se, S)
• Possible Quantum Diffusion of Polaronic Muons in Dy${}_2$Ti${}_2$O${}_7$ Spin Ice
• Probing strongly hybrid nuclear-electronic states in a model quantum ferromagnet
• Amorphous ferromagnetism and re-entrant magnetic glassiness in Sm${}_2$Mo${}_2$O${}_7$: new insights into the electronic phase diagram of pyrochlore molybdates
• Low frequency spin dynamics in XY quantum spin ice Yb${}_2$Pt${}_2$O${}_7$