Topological Valley Transport of Gapped Dirac Magnons in Bilayer Ferromagnetic Insulators

Abstract

Bilayer Heisenberg ferromagnetic insulators hold degenerate terahertz Dirac magnon modes associated with two opposite valleys of the hexagonal Brillouin zone. We show that this energy degeneracy can be removed by breaking of the inversion symmetry (I), leading to a topological magnon valley current. We show furthermore that this current leads to valley Seebeck effect for magnons and is thereby detectable. We perform calculations in the specific example of bilayer CrBr3, where I can be broken by electrostatic doping.

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Cited by in corpus (11)

• Topological Magnons: A Review
• Topological responses from gapped Weyl points in 2D altermagnets
• Insights on magnon topology and valley-polarization in 2D bilayer quantum magnets
• Nonvolatile Magnonics in Bilayer Magnetic Insulators
• Conversion of chiral phonons into magnons in ferromagnets and antiferromagnets
• Valley-polarized domain wall magnons in 2D ferromagnetic bilayers
• Magnon dispersion in bilayers of two-dimensional ferromagnets
• Theoretical realization of rich magnon topology by symmetry-breaking in honeycomb bilayer ferromagnets
• Dipolar spin-waves and tunable band gap at the Dirac points in the 2D magnet ErBr3
• Chirality-selective topological magnon phase transition induced by interplay of anisotropic exchange interactions in honeycomb ferromagnet
• Ferroelectric Switchable Topological Magnon Hall Effect in Type-I Multiferroics