Anomalous magnetic noise in imperfect flat bands in the topological magnet Dy2Ti2O7

Abstract

The spin ice compound Dy_2Ti_2O_7 stands out as the first topological magnet in three dimensions, with its tell-tale emergent fractionalized magnetic monopole excitations. Its real-time dynamical properties have been an enigma from the very beginning. Using ultrasensitive, non-invasive SQUID measurements, we show that Dy_2Ti_2O_7 exhibits a highly anomalous noise spectrum, in three qualitatively different regimes: equilibrium spin ice, a `frozen' regime extending to ultra-low temperatures, as well as a high-temperature `anomalous' paramagnet. We show that in the simplest model of spin ice, the dynamics is not anomalous, and we present several distinct mechanisms which give rise to a coloured noise spectrum. In addition, we identify the structure of the single-ion dynamics as a crucial ingredient for any modelling. Thus, the dynamics of spin ice Dy_2Ti_2O_7 reflects the interplay of local dynamics with emergent topological degrees of freedom and a frustration-generated imperfectly flat energy landscape, and as such should be relevant for a broad class of magnetic materials.

arXiv commentArticle+Sup. Info

References in corpus (25)

• Spin Ice State in Frustrated Magnetic Pyrochlore Materials
• Magnetic Monopoles in Spin Ice
• Spin Ice, Fractionalization and Topological Order
• Signature of magnetic monopole and Dirac string dynamics in spin ice
• Why spin ice obeys the ice rules
• Low Temperature Spin Freezing in Dy2Ti2O7 Spin Ice
• Magnetic Monopole Dynamics in Spin Ice
• Vacancy defects and monopole dynamics in oxygen-deficient pyrochlores
• Machine Learning Assisted Insight to Spin Ice Dy${}_2$Ti${}_2$O${}_7$
• Disordered flat bands on the kagome lattice
• Spin Dynamics at Very Low Temperature in Spin Ice Dy${}_2$Ti${}_2$O${}_7$
• Magnetic Monopole Noise
• Unconventional magnetization processes and thermal runaway in spin-ice Dy${}_2$Ti${}_2$O${}_7$
• Dynamics of the Magnetic Susceptibility Deep in the Coulomb Phase of the Dipolar Spin Ice Material Ho2Ti2O7
• Far from equilibrium monopole dynamics in spin ice
• Spin slush in an extended spin ice model
• Aging, memory, and nonhierarchical energy landscape of spin jam
• Single-ion anisotropy and magnetic field response in spin ice materials Ho${}_2$Ti${}_2$O${}_7$ and Dy${}_2$Ti${}_2$O${}_7$
• A Supercooled Spin Liquid State in the Frustrated Pyrochlore Dy2Ti2O7
• Magnetocaloric Study of Spin Relaxation in `Frozen' Dipolar Spin Ice Dy2Ti2O7
• Experimental signature of the attractive Coulomb force between positive and negative magnetic monopoles in spin ice
• AC Wien effect in spin ice, manifest in non-linear non-equilibrium susceptibility
• Jammed spin liquid in the bond-disordered kagome Heisenberg antiferromagnet
• Phonon-mediated spin-flipping mechanism in the spin ices Dy${}_2$Ti${}_2$O${}_7$ and Ho${}_2$Ti${}_2$O${}_7$
• Nuclear spin assisted quantum tunnelling of magnetic monopoles in spin ice

Cited by in corpus (14)

• Dynamical fractal and anomalous noise in a clean magnetic crystal
• Structural magnetic glassiness in spin ice Dy${}_2$Ti${}_2$O${}_7$
• Spiral Spin Liquid Noise
• Dichotomous Dynamics of Magnetic Monopole Fluids
• Spin ice in a general applied magnetic field: Kasteleyn transition, magnetic torque and rotational magnetocaloric effect
• [111]-strained spin ice: Localization of thermodynamically deconfined monopoles
• Deconstructing Magnetization Noise: Degeneracies, Phases, and Mobile Fractionalized Excitations in Tetris Artificial Spin Ice
• 2-Form U(1) Spin Liquids: Classical Model and Quantum Aspects
• Thermodynamics and fractal dynamics of nematic spin ice, a doubly frustrated pyrochlore Ising magnet
• Power spectrum of magnetic relaxation in spin ice: anomalous diffusion in a Coulomb fluid
• Scaling study of diffusion in dynamic crowded spaces
• Random Transverse Field Effects on Magnetic Noise in Spin Systems
• Spinon mediation of witness spin dynamics in herbertsmithite
• Hearing the light: stray-field noise from the emergent photon in quantum spin ice