Spin Dynamics at Very Low Temperature in Spin Ice Dy${}_2$Ti${}_2$O${}_7$

Abstract

We have performed AC susceptibility and DC magnetic relaxation measurements on the spin ice system Dy${}_2$Ti${}_2$O${}_7$ down to 0.08 K. The relaxation time of the magnetization has been estimated below 2 K down to 0.08 K. The spin dynamics of Dy${}_2$Ti${}_2$O${}_7$ is well described by using two relaxation times (${\tau }_{\mathrm{S}}$ (short time) and ${\tau }_{\mathrm{L}}$ (long time)). Both ${\tau }_{\mathrm{S}}$ and ${\tau }_{\mathrm{L}}$ increase on cooling. Assuming the Arrhenius law in the temperature range 0.5-1 K, we obtained an energy barrier of 9 K. Below 0.5 K, both ${\tau }_{\mathrm{S}}$ and ${\tau }_{\mathrm{L}}$ show a clear deviation from the thermal activated dynamics toward temperature independent relaxation, suggesting a quantum dynamics.

4 pages

References in corpus (3)

• Dirac Strings and Magnetic Monopoles in Spin Ice Dy2Ti2O7
• Low Temperature Spin Freezing in Dy2Ti2O7 Spin Ice
• Observation of Magnetic Monopoles in Spin Ice

Cited by in corpus (7)

• Vacancy defects and monopole dynamics in oxygen-deficient pyrochlores
• Brownian Motion and Quantum Dynamics of Magnetic Monopoles in Spin Ice
• Fragmentation in Frustrated Magnets -- A review
• An irreversible magnetic-field dependence of low-temperature heat transport of spin-ice compound Dy_2Ti_2O_7 in a [111] field
• Dynamic behavior of magnetic avalanches in the spin-ice compound Dy${}_2$Ti${}_2$O${}_7$
• Violation of the fluctuation-dissipation theorem and effective temperatures in spin ice
• The monopole movement