Valley-polarized domain wall magnons in 2D ferromagnetic bilayers

Abstract

Valleytronics is a pioneering technological field relying on the valley degree of freedom to achieve novel electronic functionalities. Topological valley-polarized electrons confined to domain walls in bilayer graphene were extensively studied in view of their potentials in valleytronics. Here, we study the magnonic version of domain wall excitations in 2D honeycomb ferromagnetic bilayers (FBL) with collinear order. In particular, we explore the implications of Dzyaloshinskii-Moriya interaction (DMI) and electrostatic doping (ED) on the existence and characteristics of 1D magnons confined to layer stacking domain walls in FBL. The coexistence of DMI and ED is found to enrich the topology in FBL, yet the corresponding domain wall magnons do not carry a well-defined valley index. On the other hand, we show that layer stacking domain walls in DMI-free FBL constitute 1D channels for ballistic transport of topological valley-polarized magnons. Our theoretical results raise hope towards magnon valleytronic devices based on atomically thin topological magnetic materials.

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Cited by in corpus (5)

• Quantum Valley Hall effect without Berry curvature
• Insights on magnon topology and valley-polarization in 2D bilayer quantum magnets
• Theoretical realization of rich magnon topology by symmetry-breaking in honeycomb bilayer ferromagnets
• Edge state in AB-stacked bilayer graphene and its correspondence with SSH ladder
• Dipolar spin-waves and tunable band gap at the Dirac points in the 2D magnet ErBr3