Quantum and Classical Glass Transitions in $Li Ho_x Y_{1-x} F_4$

TL;DR

This paper investigates the quantum and classical glass transitions in the Ising magnet $ ext{LiHo}_x ext{Y}_{1-x} ext{F}_4$, revealing a spin glass transition at specific concentrations and contrasting classical and quantum behaviors under different conditions.

Contribution

It demonstrates the existence of a spin glass transition in $ ext{LiHo}_x ext{Y}_{1-x} ext{F}_4$ and explores how quantum effects alter the transition at high transverse fields.

Findings

Spin glass transition observed at $x$=0.167 and 0.198.

Classical behavior persists at low fields.

Quantum regime shows different behavior due to entanglement and random fields.

Abstract

When performed in the proper low field, low frequency limits, measurements of the dynamics and the nonlinear susceptibility in the model Ising magnet in transverse field, $\text{LiHo}_x\text{Y}_{1-x}\text{F}_4$, prove the existence of a spin glass transition for $x$ = 0.167 and 0.198. The classical behavior tracks for the two concentrations, but the behavior in the quantum regime at large transverse fields differs because of the competing effects of quantum entanglement and random fields.