English

Thermoelastic enhancement of the magnonic spin Seebeck effect in thin films and bulk samples

Mesoscale and Nanoscale Physics 2018-05-09 v1

Abstract

A non-uniform temperature profile may generate a pure spin current in magnetic films, as observed for instance in the spin Seebeck effect. In addition, thermally induced elastic deformations may set in that could affect the spin current. A self-consistent theory of the magnonic spin Seebeck effect including thermally activated magneto-elastic effects is presented and analytical expressions for the thermally activated deformation tensor and dispersion relations for coupled magneto-elastic modes are obtained. We derived analytical results for bulk (3D) systems and thin magnetic (2D) films. We observed that the displacement vector and the deformation tensor in bulk systems decay asymptotically as u1/R2u\sim1/R^{2} and ε1/R3\varepsilon\sim1/R^{3}, respectively, while the decays in thin magnetic films proceed slower following u1/Ru\sim1/R and ε1/R2\varepsilon\sim1/R^{2}. The dispersion relations evidence a strong anisotropy in the magnetic excitations. We observed that a thermoelastic steady state deformation may lead to both an enchantment or a reduction of the gap in the magnonic spectrum. The reduction of the gap increases the number of magnons contributing to the spin Seebeck effect and offers new possibilities for the thermoelastic control of the Spin Seebeck effect.

Keywords

Cite

@article{arxiv.1804.02185,
  title  = {Thermoelastic enhancement of the magnonic spin Seebeck effect in thin films and bulk samples},
  author = {L. Chotorlishvili and X. -G. Wang and Z. Toklikishvili and J. Berakdar},
  journal= {arXiv preprint arXiv:1804.02185},
  year   = {2018}
}

Comments

to appear in Phys. Rev. B