Emergent electric field and resonance dynamics in a one-dimensional chiral magnet driven by an AC magnetic field*

Swirling spin textures like magnetic skyrmions bring about an emergent magnetic field (EMF) through the Berry phase, resulting in transport phenomena like the topological Hall effect. Dynamics of such spin textures can generate an emergent electric field (EEF), leading to exotic electronic properties such as emergent inductance. The EMF appears in two- and three-dimensional systems since it emerges as a fictitious magnetic flux through the plaquette accompanied by surrounding noncoplanar spin textures. In contrast, the EEF arises from time evolution of noncollinear spin textures, and can be generated in a broader range of magnets including one-dimensional systems. To elucidate the fundamental behavior of the EEF, in this study, we theoretically investigate the EEF under an AC magnetic field in a one-dimensional chiral magnet [1]. We show that the bulk EEF is prominent at the magnetic resonant modes and amplified by the solitonic feature of spin textures. Furthermore, we reveal that a comparable contribution arises from the excitation modes at the edges of the system appearing within the magnon band gap. We also demonstrate that the magnetic resonances exhibit peculiar dynamics such as soliton penetration and unidirectional soliton transport. Our systematic studies on the EEF and the resonance dynamics would pave the way for the applications of one-dimensional chiral magnets to electronic and magnetic devices.

[1] K. Shimizu et al., arXiv:2307.08017 (2023).