A new macroscopically degenerate ground state in the spin ice compound Dy2Ti2O7 under a magnetic field

TL;DR

This paper investigates the magnetic behavior of Dy2Ti2O7 under a magnetic field, revealing a disordered plateau state with significant residual entropy and a transition indicating the breaking of the spin ice state.

Contribution

It uncovers a new macroscopically degenerate ground state in Dy2Ti2O7 under magnetic field, highlighting the role of spin frustration in the kagome layers.

Findings

Observation of a magnetization plateau below 1 K in 2-9 kOe range

Identification of a sharp moment jump at around 10 kOe

Residual entropy approximately half of the zero-field state

Abstract

The low temperature magnetic properties of pyrochlore compound Dy2Ti2O7 in magnetic fields applied along the [111] direction are reported. Below 1 K, a clear plateau has been observed in the magnetization process in the field range 2~9 kOe, followed by a sharp moment jump at around 10 kOe that corresponds to a breaking of the spin ice state. We found that the plateau state is disordered with the residual entropy of nearly half the value of the zero-field state, whose macroscopic degeneracy comes from a frustration of the spins on the kagome layers perpendicular to the magnetic field.