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arXiv 1904.01151cond-mat.mes-hallcond-mat.mtrl-scicond-mat.quant-gascond-mat.stat-mechcond-mat.str-el
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通用$1/3$ -扩散绝缘磁体中的磁散粒噪声的抑制

Universal $1/3$-suppression of magnonic shot noise in diffusive insulating magnets

Kouki Nakata, Yuichi Ohnuma, Mamoru Matsuo

摘要:

扩展玻尔兹曼-朗之万理论的磁振子,我们显示了一个普遍性的电流噪声抑制扩散系统对玻色子和费米子的量子统计特性的差异。为此,从一个量子动力学方程的磁振子进行热梯度在稀杂质,我们推导出一个玻色子对应的半经典玻尔兹曼-朗之万方程的电子和评估磁振子电流噪声的扩散绝缘磁体。我们从理论上发现,与绝缘铁磁结中磁振子的泊松散粒噪声相比,扩散绝缘体磁体中的磁振子散粒噪声被抑制,低温下的噪声电流比(Fano因子)表现出普遍的行为,即,与扩散导体中电子输运相同的抑制$1/3$,尽管量子统计性质不同。最后,我们表明,我们的预测是在实验范围内与目前的设备和测量技术。

英文摘要:

Extending a Boltzmann-Langevin theory to magnons, we show a universality of current-noise suppression in diffusive systems against the difference of quantum-statistical properties of bosons and fermions. To this end, starting from a quantum kinetic equation for magnons subjected to thermal gradient in dilute impurities, we derive a bosonic counterpart of the semiclassical Boltzmann-Langevin equation for electrons and evaluate a magnonic current-noise in the diffusive insulating magnet. We theoretically discover that compared with a Poissonian shot noise of magnons in an insulating ferromagnetic junction, the magnonic shot noise is suppressed in the diffusive insulating bulk magnet and noise-to-current ratio (Fano factor) at low temperatures exhibits a universal behavior, i.e., the same suppression $1/3$ as the one for electron transport in diffusive conductors, despite the difference of quantum-statistical properties. Finally, we show that our predictions are within experimental reach with current device and measurement technologies.

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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