Neutron scattering from fragmented frustrated magnets

TL;DR

This paper uses the fragmentation approach to analyze neutron scattering in kagomé ice and spin ice, revealing how quantum fluctuations influence ordering and providing a diagnostic for quantum effects.

Contribution

It introduces a fragmentation-based framework to interpret neutron scattering data and analyze quantum fluctuation effects in frustrated magnetic systems.

Findings

Quantum fluctuations induce a double-q structure in kagomé ice.

Intensity reduction of Bragg peaks indicates quantum fluctuations.

Quantum Monte Carlo data supports the proposed analysis protocol.

Abstract

The fragmentation description is used to analyse calculated neutron scattering intensities from kagom\'e ice and spin ice systems. The longitudinal, transverse and harmonic fragments produce independent contributions to the neutron scattering intensity. This framework is used to analyse the ordering due to quantum fluctuations in the topologically constrained phase of kagom\'e ice and the monopole crystal phase of spin ice. Here, quantum fluctuations are restricted to the transverse fragment and they drive the system into a double-$q$ structure in which longitudinal and transverse fragments have a different ordering wave vector. The intensity reduction of the Bragg peaks for the transverse fragments, compared with known classical limits can be used as a diagnostic tool for quantum fluctuations. Published quantum Monte Carlo data for spin ice in a $[111]$ field are consistent with the proposed protocol.