Magnon spin transport driven by the magnon chemical potential in a magnetic insulator
Magnon spin transport driven by the magnon chemical potential in a magnetic insulator
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DOI：
10.1103/physrevb.94.014412
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发表时间：
2016-07-11
影响因子：
3.7
通讯作者：
van Wees, B. J.
中科院分区：
文献类型：
--
作者：
Cornelissen, L. J.;Peters, K. J. H.;van Wees, B. J.
我们发展了一个线性响应输运理论的扩散自旋和热输运的磁振子在磁性绝缘体与金属接触。磁振子描述的位置依赖的温度和化学势，由扩散方程与特征弛豫长度。从线性化的玻尔兹曼方程出发，我们推导出长度尺度和输运系数的表达式。对于钇铁石榴石（YIG）在室温下，我们发现，长程输运是由磁振子化学势占主导地位。我们比较了模型的结果与最近的实验YIG与Pt接触[L。J. Cornelissen等人，11，1022（2015）]并提取σ（m）= 5 × 10（5）S/m的磁振子自旋电导率。我们的结果的自旋Seebeck系数在YIG同意与已发表的实验。我们的结论是磁振子化学势是一个必不可少的成分的能量和自旋输运的磁性绝缘体。
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 et al., Nat. Phys. 11, 1022 (2015)] and extract a magnon spin conductivity of sigma(m) = 5 x 10(5) 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.