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arXiv · 1812.08741

Unidirectional spin-wave channeling along magnetic domain walls of Bloch type

Yves Henry·Daniel Stoeffler·Joo-Von Kim·Matthieu Bailleul
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Abstract

From the pioneering work of Winter [Phys. Rev. 124, 452 (1961)], a magnetic domain wall of Bloch type is known to host a special wall-bound spin-wave mode, which corresponds to spin-waves being channeled along the magnetic texture. Using micromagnetic simulations, we investigate spin-waves travelling inside Bloch walls formed in thin magnetic media with perpendicular-to-plane magnetic anisotropy and we show that their propagation is actually strongly nonreciprocal, as a result of dynamic dipolar interactions. We investigate spin-wave non-reciprocity effects in single Bloch walls, which allows us to clearly pinpoint their origin, as well as in arrays of parallel walls in stripe domain configurations. For such arrays, a complex domain-wall-bound spin-wave band structure develops, some aspects of which can be understood qualitatively from the single-wall picture by considering that a wall array consists of a sequence of up/down and down/up walls with opposite non-reciprocities. Circumstances are identified in which the non-reciprocity is so extreme that spin-wave propagation inside individual walls becomes unidirectional.

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Yves Henry, Daniel Stoeffler, Joo-Von Kim, Matthieu Bailleul. 2018-12-20. Unidirectional spin-wave channeling along magnetic domain walls of Bloch type. https://doi.org/10.1103/physrevb.100.024416

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