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MA: Fachverband Magnetismus
MA 52: Poster II
MA 52.27: Poster
Thursday, March 15, 2018, 15:00–18:00, Poster C
Critical exponents of magnon transport coefficients — Alexander Mook1, •Till Hanke1, Jürgen Henk1, and Ingrid Mertig1,2 — 1Institut für Physik, Martin-Luther-Universität, D-06120 Halle — 2Max-Planck-Institut für Mikrostrukturphysik, D-06120 Halle
The spin and heat transport through magnetic insulators is a centerpiece in the fields of spintronics, spin caloritronics, and magnonics. We report on the development of a method that simulates magnon transport over the entire temperature range, from zero Kelvin up to and beyond the critical temperature. It is based on equilibrium atomistic spin dynamics simulations and the Green-Kubo relations [1], relating the equilibrium fluctuations of currents to the magnon transport coefficients, such as the spin conductivitiy σ, the spin Seebeck coefficient S, and the thermal conductivity κ. We study the dependence of these conductivities on temperature in generic three-dimensional magnets. Focussing on the thermal second-order phase transition from the ordered to the paramagnetic phase, we extract the critical exponents of σ, S, and κ. The connection to recent experimental results on the spin Seebeck effect in yttrium iron garnet [2] is discussed.
[1] A. Mook et al., Phys. Rev. B 94, 174444 (2016)
[2] K. Uchida et al., Phys. Rev. X 4, 041023 (2014)