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arXiv 1209.3405cond-mat.mtrl-scicond-mat.other
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揭开磁振子-声子耦合的掩蔽:磁振子温度的直接测量

Magnon-phonon coupling unmasked: a direct measurement of magnon temperature

Milan Agrawal, Vitaliy I. Vasyuchka, Alexander A. Serga, Alexy D. Karenowska, Gennadiy A. Melkov, Burkard Hillebrands

摘要:

磁性材料中的热电现象为在未来的“自旋热电子”器件中利用热来操纵自旋信息提供了诱人的可能性。解开其基础物理的关键是理解自旋-晶格相互作用,即磁振子(磁化激发的量子)和声子(晶格振动的量子)之间的耦合。在这里,我们提出的第一次测量的磁振子温度的空间分布的磁系统受到横向热(即声子温度)梯度,并证明,与目前公认的理论,磁振子和声子温度没有不同。这一结果具有深远的意义。特别是,它重新开启了自旋塞贝克效应如何存在的问题,以及它的物理基础是什么。自旋塞贝克效应允许自旋电流从热梯度中产生,可以说是所有热电现象中最有趣和技术相关的现象。具体来说,它揭示了如果当前效应理论的一般框架成立,我们必须采用一个新的概念,即光谱不均匀的磁振子温度。

英文摘要:

Thermoelectric phenomena in magnetic materials present tantalizing possibilities for manipulating spin-information using heat in future 'spin caloritronic' devices. Key to unraveling their underlying physics is to understand spin-lattice interactions, i.e. the coupling between magnons (the quanta of magnetization excitations) and phonons (the quanta of lattice vibrations). Here, we present the first measurements of the spatial distribution of magnon temperature in a magnetic system subject to a lateral thermal (i.e. phonon temperature) gradient and demonstrate that, contrary to currently accepted theory, the magnon and phonon temperatures do not differ. This result has profound implications. In particular, it re-opens the question of how the spin Seebeck effect-which allows spin currents to be produced from thermal gradients, and is arguably the most intriguing and technologically relevant thermoelectric phenomenon of all-can exist, and which physics underpins it. Specifically, it reveals that if the general framework of the current theory of the effect holds, we must adopt a new concept of spectrally non-uniform magnon temperature.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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