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${}_7$.

9 pages, 4 figures

References in corpus (3)

• Dirac Strings and Magnetic Monopoles in Spin Ice Dy2Ti2O7
• Disordered Route to the Coulomb Quantum Spin Liquid: Random Transverse Fields on Spin Ice in Pr${}_2$Zr${}_2$O${}_7$
• Quenched crystal field disorder and magnetic liquid ground states in Tb2Sn2-xTixO7

Cited by in corpus (8)

• Melting of Spin Ice state through structural disorder in Dy2Zr2O7
• 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
• Revisiting spin ice physics in the ferromagnetic Ising pyrochlore Pr${}_2$Sn${}_2$O${}_7$
• Traversing the pyrochlore stability diagram; microwave-assisted synthesis and discovery of mixed B-site Ln${}_2$InSbO${}_7$ family
• 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