Tuneable terahertz oscillation arising from Bloch-point dynamics in chiral magnets

TL;DR

This paper predicts that the dynamics of Bloch points in chiral magnets can generate tunable terahertz signals, offering a new approach for skyrmion-based electronic devices by controlling topological singularities.

Contribution

It introduces a theoretical framework linking Bloch-point dynamics to terahertz emission and proposes methods to control this process for device applications.

Findings

Bloch-point propagation induces terahertz electric fields.

Control of Bloch-point dynamics tunes terahertz signal frequency and amplitude.

Topological singularities can be exploited for skyrmion-based electronics.

Abstract

Skyrmionic textures are being extensively investigated due to the occurrence of novel topological magnetic phenomena and their promising applications in a new generation of spintronic devices that take advantage of the robust topological stability of their spin structures. The development of practical devices relies on a detailed understanding of how skyrmionic structures can be formed, transferred, detected and annihilated. In this work, our considerations go beyond static skyrmions and theoretically show that the formation/annihilation of both skyrmions and antiskyrmions is enabled by the transient creation and propagation of topological singularities (magnetic monopole-like Bloch points). Critically, during the winding/unwinding of skyrmionic textures, our results predict that the Bloch-point propagation will give rise to an emergent electric field in a terahertz frequency range and with substantial amplitude. We also demonstrate ways for controlling Bloch-point dynamics, which directly enable the tuneability on both frequency and amplitude of this signal. Our studies provide a concept of directly exploiting topological singularities for terahertz skyrmion-based electronic devices.