Magnon drag induced by magnon-magnon interactions characteristic of noncollinear magnets
arXiv:2208.12939 · doi:10.1103/PhysRevB.106.064306
Abstract
A noncollinear magnet consists of the magnetic moments forming a noncollinear spin structure. Because of this structure, the Hamiltonian of magnons acquires the cubic terms. Although the cubic terms are the magnon-magnon interactions characteristic of noncollinear magnets, their effects on magnon transport have not been clarified yet. Here we show that in a canted antiferromagnet the cubic terms cause a magnon drag that magnons drag magnon spin current and heat current, which can be used to enhance these currents by tuning a magnetic field. For a strong magnetic field, we find that the cubic terms induce low-temperature peaks of a spin-Seebeck coefficient, a magnon conductivity, and a magnon thermal conductivity, and that each value is one order of magnitude larger than the noninteracting value. This enhancement is mainly due to the magnetic field dependence of the coupling constant of the cubic terms through the magnetic-field dependent canting angle. Our magnon drag offers a way for controlling the magnon currents of noncollinear magnets via the many-body effect.
18 pages, 5 figures; published version
References in corpus (11)
- Spin Seebeck insulator
- Spin Seebeck effect in antiferromagnets and compensated ferrimagnets
- Magnon Decay in Noncollinear Quantum Antiferromagnets
- Magnon-drag thermopile
- Temperature dependence of the magnon spin diffusion length and magnon spin conductivity in the magnetic insulator yttrium iron garnet
- Spin Drag and Spin-Charge Separation in Cold Fermi Gases
- Spin drag in an ultracold Fermi gas on the verge of a ferromagnetic instability
- Antiferromagnetic spin Seebeck effect across the spin-flop transition: A stochastic Ginzburg-Landau simulation
- Magnon Dispersion and Specific Heat of Chiral Magnets on the Pyrochlore Lattice
- Effects of magnon-magnon interactions in a noncollinear magnet induced by combination of a symmetric and an antisymmetric exchange interaction
- Interband magnon drag in ferrimagnetic insulators