Tunable large spin Nernst effect in a two-dimensional magnetic bilayer

Abstract

We theoretically investigate topological spin transport of the magnon-polarons in bilayer magnet with two-dimensional square lattices. Our theory is motivated by recent reports on the van der Waals magnets which show the reversible electrical switching of the interlayer magnetic order between antiferromagnetic and ferromagnetic orders. The magnetoelastic interaction opens band gaps and allows the interband transition between different excitation states. In the layered antiferromagnet, due to the interband transition between the magnon-polaron states, the spin Berry curvature which allows the topological spin transport occurs even if the time-reversal symmetry is preserved. We find that the spin Berry curvature in the layered antiferromagnet is very large due to the small energy spacing between two magnon-like states. As a result, the spin Nernst conductivity shows sudden increase (or decrease) at the phase transition point between ferromagnetic and antiferromagnetic phases. Our result suggest that the ubiquity of tunable topological spin transports in two dimensional magnetic systems.

12 pages, 7 figures

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Cited by in corpus (9)

• Topological Phases in Magnonics
• Tunable topological magnon-polaron states and anomalous Hall phenomena in two-dimensional ferromagnetic insulators
• Giant spin Nernst effect in a two-dimensional antiferromagnet due to magnetoelastic coupling-induced gaps and interband transitions between magnon-like bands
• Topological magnon gap engineering in van der Waals CrI${}_3$ ferromagnets
• Topological magnon-polarons in honeycomb antiferromagnets with spin-flop transition
• Magnon dispersion and spin transport in CrCl${}_3$ bilayers under different strain-induced magnetic states
• Topological magnon-polaron transport in a bilayer van der Waals magnet
• Formulation of spin Nernst effect for spin-nonconserving insulating magnets
• Chiral Phonons Arising From Chirality-Selective Magnon-Phonon Coupling