Magnon spin transport driven by the magnon chemical potential in a magnetic insulator

Journal article (2016)

Authors

L.J. Cornelissen Rijksuniversiteit Groningen
K. J H Peters Universiteit Utrecht
G.E. Bauer Tohoku University, QN/Bauer Group - AS
Rembert A. Duine Eindhoven University of Technology, Universiteit Utrecht
B. J. Van Wees Rijksuniversiteit Groningen
Research Group
QN/Bauer Group (AS) (TU Delft)
Copyright: © 2016 L.J. Cornelissen, K. J H Peters, G.E. Bauer, R. A. Duine, B. J. Van Wees
DOI
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https://doi.org/10.1103/PhysRevB.94.014412
More Info
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Published Date

11-07-2016

Language

English

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Faculty

Applied Sciences

Department

QN/Quantum Nanoscience

Research Group

QN/Bauer Group

Abstract

We develop a linear-response transport theory of diffusive spin and heat transport by magnons in magnetic insulators with metallic contacts. The magnons are described by a position-dependent temperature and chemical potential that are governed by diffusion equations with characteristic relaxation lengths. Proceeding from a linearized Boltzmann equation, we derive expressions for length scales and transport coefficients. For yttrium iron garnet (YIG) at room temperature we find that long-range transport is dominated by the magnon chemical potential. We compare the model's results with recent experiments on YIG with Pt contacts [L. J. Cornelissen, Nat. Phys. 11, 1022 (2015)1745-247310.1038/nphys3465] and extract a magnon spin conductivity of σm=5×105 S/m. Our results for the spin Seebeck coefficient in YIG agree with published experiments. We conclude that the magnon chemical potential is an essential ingredient for energy and spin transport in magnetic insulators.