Stacking-dependent topological magnons in bilayer CrI${}_3$

Abstract

Motivated by the potential of atomically-thin magnets towards tunable high-frequency magnonics, we detail the spin-wave dispersion of bilayer CrI${}_3$. We demonstrate that the magnonic behavior of the bilayer strongly depends on its stacking configuration and the interlayer magnetic ordering, where a topological bandgap opens in the dispersion caused by the Dzyaloshinskii-Moriya and Kitaev interactions, classifying bilayer CrI${}_3$ as a topological magnon insulator. We further reveal that both size and topology of the bandgap in a CrI${}_3$ bilayer with an antiferromagnetic interlayer ordering are tunable by an external magnetic field.

References in corpus (12)

• Magnetic 2D materials and heterostructures
• Dirac materials
• Probing magnetism in 2D materials at the nanoscale with single spin microscopy
• Spirit: Multifunctional Framework for Atomistic Spin Simulations
• Dirac magnons in honeycomb ferromagnets
• Magnetic field effect on topological spin excitations in CrI${}_3$
• First-principle calculation of Chern number in gyrotropic photonic crystals
• Topological magnon insulator spin excitations in the two-dimensional ferromagnet CrBr${}_3$
• Topological magnon band structure of emergent Landau levels in a skyrmion lattice
• Distinctive magnetic properties of CrI3 and CrBr3 monolayers caused by spin-orbit coupling
• The interplay of Dzyaloshinskii-Moriya and Kitaev interactions for magnonic properties of Heisenberg-Kitaev honeycomb ferromagnets
• Massless Dirac magnons in the two dimensional van der Waals honeycomb magnet CrCl3