Magnetic field effect on topological spin excitations in CrI${}_3$

Abstract

The search for topological spin excitations in recently discovered two-dimensional (2D) van der Waals (vdW) magnetic materials is important because of their potential applications in dissipation-less spintronics. In the 2D vdW ferromagnetic (FM) honeycomb lattice CrI${}_3$(T${}_C$= 61 K), acoustic and optical spin waves were found to be separated by a gap at the Dirac points. The presence of such a gap is a signature of topological spin excitations if it arises from the next nearest neighbor(NNN) Dzyaloshinskii-Moriya (DM) or bond-angle dependent Kitaev interactions within the Cr honeycomb lattice. Alternatively, the gap is suggested to arise from an electron correlation effect not associated with topological spin excitations. Here we use inelastic neutron scattering to conclusively demonstrate that the Kitaev interactions and electron correlation effects cannot describe spin waves, Dirac gap and their in-plane magnetic field dependence. Our results support the DM interactions being the microscopic origin of the observed Dirac gap. Moreover, we find that the nearest neighbor (NN) magnetic exchange interactions along the axis are antiferromagnetic (AF)and the NNN interactions are FM. Therefore, our results unveil the origin of the observedcaxisAF order in thin layers of CrI${}_3$, firmly determine the microscopic spin interactions in bulk CrI${}_3$, and provide a new understanding of topology-driven spin excitations in 2D vdW magnets.

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Cited by in corpus (44)

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• Anisotropic magnon damping by zero-temperature quantum fluctuations in ferromagnetic CrGeTe${}_3$
• Gaps in Topological Magnon Spectra: Intrinsic vs. Extrinsic Effects
• Stacking-dependent topological magnons in bilayer CrI${}_3$
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• Observation of spin-wave moiré edge and cavity modes in twisted magnetic lattices
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• Tunable magnon topology in monolayer CrI${}_3$ under external stimuli
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• Tunable topological magnon-polaron states and anomalous Hall phenomena in two-dimensional ferromagnetic insulators
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• Thermal Hall effect in a van der Waals ferromagnet CrI3
• Observation of helimagnetism in the candidate ferroelectric CrI${}_2$
• Signatures of Kitaev interactions in the van der Waals ferromagnet VI3
• Topological magnon gap engineering in van der Waals CrI${}_3$ ferromagnets
• Exchange interactions and spin dynamics in the layered honeycomb ferromagnet CrI${}_3$
• Intrinsic Nernst effect of the magnon orbital moment in a honeycomb ferromagnet
• Spin Waves and Dirac Magnons in a Honeycomb Lattice Zig-zag Antiferromagnet BaNi2(AsO4)2
• First-principles study of the gap in the spin excitation spectrum of the CrI${}_3$ honeycomb ferromagnet
• Superexchange and spin-orbit coupling in monolayer and bilayer chromium trihalides
• Antiferromagnetic-ferromagnetic homostructures with Dirac magnons in van der Waals magnet CrI${}_3$
• Thermal Transport Properties of Magnons on the $\alpha$-T${}_3$ Lattice
• Sign Changes in Heat, Spin, and Orbital Magnon Transport Coefficients in Kitaev Ferromagnets
• Skyrmions in van der Waals centrosymmetric materials with Dzyaloshinskii-Moriya interactions
• Intrinsic Spin Nernst Effect and Chiral Edge Modes in van der Waals Ferromagnetic Insulators: Dzyaloshinskii-Moriya vs. Kitaev Interactions
• Magnon dispersion and spin transport in CrCl${}_3$ bilayers under different strain-induced magnetic states
• Local spin-flip transitions induced by magnetic quantum impurities in two-dimensional magnets
• Helimagnetism in CrBr${}_2$ and CrIBr
• Magnon sensing of NO, NO${}_2$ and NH${}_3$ gas capture on CrSBr monolayer
• Topological magnon-polaron transport in a bilayer van der Waals magnet
• Interlayer superexchange in bilayer chromium trihalides
• Interacting Dirac magnons in the van der Waals ferromagnet CrBr${}_3$
• Angular-Dependent Thermal Hall Effect in a Honeycomb Magnet: Disentangling Kitaev and Dzyaloshinskii-Moriya Interactions
• Scattering Theory of Chiral Edge Modes in Topological Magnon Insulators
• Magnetic Order and Magneto-Elasticity in the Electronic Excitations of Gd-$i$-MAX
• Spin-orbit coupling controlled two-dimensional magnetism in chromium trihalides
• Impact of the honeycomb spin-lattice on topological magnons and edge states in ferromagnetic 2D skyrmion crystals
• Evidence for magnetoelastic coupling and chiral magnetic ground state in quasi-van der Waals tr-Cr${}_{1.22}$Te${}_2$
• Self-consistent renormalized spin-wave theory of magnetic and topological transitions in two-dimensional honeycomb ferromagnets