Topological chiral magnonic edge mode in a magnonic crystal

Physical review. B, Condensed matter (Impact Factor: 3.66). 04/2012; 87(17). DOI: 10.1103/PhysRevB.87.174427
Source: arXiv

ABSTRACT Topological phases have been explored in various fields in physics such as
spintronics, photonics, liquid helium, correlated electron system and
cold-atomic system. This leads to the recent foundation of emerging materials
such as topological band insulators, topological photonic crystals and
topological superconductors/superfluid. In this paper, we propose a topological
magnonic crystal which provides protected chiral edge modes for magnetostatic
spin waves. Based on a linearized Landau-Lifshitz equation, we show that a
magnonic crystal with the dipolar interaction acquires spin-wave volume-mode
band with non-zero Chern integer. We argue that such magnonic systems are
accompanied by the same integer numbers of chiral spin-wave edge modes within a
band gap for the volume-mode bands. In these edge modes, the spin wave
propagates in a unidirectional manner without being scattered backward, which
implements novel fault-tolerant spintronic devices.

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