Spin current compensation from competing magnon modes in ferrimagnets
arXiv:2505.22315 · doi:10.1088/1361-6463/adfaa0
Abstract
We investigate thermal spin pumping in gadolinium iron garnet (GdIG), focusing on the mode-resolved dynamics of antiferromagnetic magnons and their impact on spin and heat transport. Antiferromagnets support both right-handed and left-handed magnon modes, which we treat as positive and negative frequency branches, analogous to electrons and holes in semiconductors. Using a two-sublattice model with a minimal exchange interaction scheme, we derive the temperature-dependent spin-wave spectrum and evaluate the associated thermal spin pumping coefficients. Our analysis reveals that the competition between left- and right-handed modes gives rise to a compensation temperature, where the net thermally generated spin current vanishes. Importantly, we show that this compensation point does not necessarily coincide with the crossing of magnon dispersion branches. While previous research considers a detailed microscopic model including all magnetic sublattices and exchange couplings, our approach demonstrates that key features of mode-resolved spin transport can be captured by a simplified and analytically transparent model. These findings advance the understanding of spin-caloritronic phenomena in ferrimagnets and offer new perspectives for the design of chiral magnon-based spintronic devices.
References in corpus (14)
- Long distance transport of magnon spin information in a magnetic insulator at room temperature
- Theory of magnon-driven spin Seebeck effect
- Spin Nernst Effect of Magnons in Collinear Antiferromagnets
- Critical suppression of spin Seebeck effect by magnetic fields
- Thermal spin dynamics of yttrium iron garnet
- Long-distance spin-transport across the Morin phase transition up to room temperature in ultra-low damping single crystals of the antiferromagnet α-Fe2O3
- Magnon mode selective spin transport in compensated ferrimagnets
- Antiferromagnetic magnon spintronic based on non-reciprocal and non-degenerated ultra-fast spin-waves in the canted antiferromagnet α-Fe2O3
- Spin Seebeck power generators
- First-principles study of magnon-phonon interactions in gadolinium iron garnet
- Extreme Terahertz Magnon Multiplication Induced by Resonant Magnetic Pulse Pairs
- Generation of third-harmonic spin oscillation from strong spin precession induced by terahertz magnetic near fields
- Effect of interfacial spin mixing conductance on gyromagnetic ratio of Gd substituted YFeO
- Enhancement of thermal spin pumping by orbital angular momentum of rare earth iron garnet