Magnetic excitations in the low-temperature ferroelectric phase of multiferroic YMn2O5 using inelastic neutron scattering

TL;DR

This study investigates magnetic excitations in the low-temperature ferroelectric phase of multiferroic YMn2O5 using inelastic neutron scattering, revealing magnon modes and their relation to electromagnons, and explaining the underlying microscopic mechanism.

Contribution

It provides the first detailed identification of magnon modes in YMn2O5 and links them to electromagnon peaks, elucidating the microscopic origin of low-energy electromagnons.

Findings

Identification of low-energy magnon modes.

Correlation between INS magnon peaks and optical electromagnons.

Explanation of the microscopic mechanism behind the lowest-energy electromagnon.

Abstract

We studied magnetic excitations in a low-temperature ferroelectric phase of the multiferroic YMn2O5 using inelastic neutron scattering (INS). We identify low-energy magnon modes and establish a correspondence between the magnon peaks observed by INS and electromagnon peaks observed in optical absorption [1]. Furthermore, we explain the microscopic mechanism, which results in the lowest-energy electromagnon peak, by comparing the inelastic neutron spectral weight with the polarization in the commensurate ferroelectric phase.