Evidence for the Confinement of Magnetic Monopoles in Quantum Spin Ice

Abstract

Magnetic monopoles are hypothesised elementary particles connected by Dirac strings that behave like infinitely thin solenoids. Despite decades of searches, free magnetic monopoles and their Dirac strings have eluded experimental detection, although there is substantial evidence for deconfined magnetic monopole quasiparticles in spin ice materials. Here we report the detection of a hierarchy of unequally-spaced magnetic excitations \emph{via} high resolution inelastic neutron spectroscopic measurements on the quantum spin ice candidate Pr${}_2$Sn${}_2$O${}_7$. These excitations are well-described by a simple model of monopole pairs bound by a linear potential with an effective tension of 0.642(8) K~$\cdot$Å${}^{-1}$ at 1.65~K. The success of the linear potential model suggests that these low energy magnetic excitations are direct spectroscopic evidence for the confinement of magnetic monopole quasiparticles in the quantum spin ice candidate Pr${}_2$Sn${}_2$O${}_7$.

arXiv comment9 pages, 4 figures

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Cited by in corpus (10)

• Melting of Spin Ice state through structural disorder in Dy2Zr2O7
• Theory of magnetostriction for multipolar quantum spin ice in pyrochlore materials
• Absence of moment fragmentation in the mixed $B$-site pyrochlore Nd${}_2$GaSbO${}_7$
• Signatures of hidden octupolar order from nonlinear Hall effects
• Ultrasound detection of emergent photons in generic quantum spin ice
• Traversing the pyrochlore stability diagram; microwave-assisted synthesis and discovery of mixed B-site Ln${}_2$InSbO${}_7$ family
• Revisiting spin ice physics in the ferromagnetic Ising pyrochlore Pr${}_2$Sn${}_2$O${}_7$
• 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
• Influence of controlled disorder on the dipolar spin ice state of Ho-based pyrochlores
• The contribution of magnetic monopoles to ponderomotive forces in plasmas