Domain-wall-induced electromagnons in multiferroics

Using an atomistic approach, we predict the emergence of hybrid quasiparticles, namely, domain-wall-induced electromagnons, that arise from dynamical couplings between magnons and optical phonons in systems possessing ferroelectric domain walls. These quasiparticles induce THz resonances in magnetoelectric responses and preferentially localize either near the domain walls or near the middle of domains. Such behavior is explained through dispersion analysis that allows us to track the emergent multidomain excitations back to single-domain magnetoelectric (ME) modes. The latter, scattered by a periodic array of domain walls, are shown to endow the domain-wall-induced electromagnons with a mixed localized mode and standing- or propagating-wave characters. Such features can be exploited to reach strikingly large ME conversion and design more reliable and ultrafast ME devices with less energy consumption and using, e.g., local probes.

Automated summary

This study predicts and investigates the emergence of domain-wall-induced electromagnons in systems with ferroelectric domain walls, resulting from dynamical couplings between magnons and optical phonons. These electromagnons induce THz resonances in magnetoelectric responses and can be localized near the domain walls or near the middle of domains. Dispersion analysis reveals the behavior and traces it back to single-domain magnetoelectric modes.